1 /* 2 * Copyright (C) 2014 BlueKitchen GmbH 3 * 4 * Redistribution and use in source and binary forms, with or without 5 * modification, are permitted provided that the following conditions 6 * are met: 7 * 8 * 1. Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer. 10 * 2. Redistributions in binary form must reproduce the above copyright 11 * notice, this list of conditions and the following disclaimer in the 12 * documentation and/or other materials provided with the distribution. 13 * 3. Neither the name of the copyright holders nor the names of 14 * contributors may be used to endorse or promote products derived 15 * from this software without specific prior written permission. 16 * 4. Any redistribution, use, or modification is done solely for 17 * personal benefit and not for any commercial purpose or for 18 * monetary gain. 19 * 20 * THIS SOFTWARE IS PROVIDED BY BLUEKITCHEN GMBH AND CONTRIBUTORS 21 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 22 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS 23 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL MATTHIAS 24 * RINGWALD OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, 25 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, 26 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS 27 * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED 28 * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, 29 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF 30 * THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 31 * SUCH DAMAGE. 32 * 33 * Please inquire about commercial licensing options at 34 * [email protected] 35 * 36 */ 37 38 #include <stdio.h> 39 #include <string.h> 40 #include <inttypes.h> 41 42 #include "ble/le_device_db.h" 43 #include "ble/core.h" 44 #include "ble/sm.h" 45 #include "btstack_debug.h" 46 #include "btstack_event.h" 47 #include "btstack_linked_list.h" 48 #include "btstack_memory.h" 49 #include "gap.h" 50 #include "hci.h" 51 #include "l2cap.h" 52 53 #ifdef ENABLE_LE_SECURE_CONNECTIONS 54 // TODO: remove software AES 55 #include "rijndael.h" 56 #endif 57 58 #if defined(ENABLE_LE_SECURE_CONNECTIONS) && !defined(HAVE_HCI_CONTROLLER_DHKEY_SUPPORT) 59 #define USE_MBEDTLS_FOR_ECDH 60 #endif 61 62 #ifdef ENABLE_LE_SECURE_CONNECTIONS 63 #ifdef HAVE_HCI_CONTROLLER_DHKEY_SUPPORT 64 #error "Support for DHKEY Support in HCI Controller not implemented yet. Please use software implementation" 65 #else 66 #define USE_MBEDTLS_FOR_ECDH 67 #endif 68 #endif 69 70 71 // Software ECDH implementation provided by mbedtls 72 #ifdef USE_MBEDTLS_FOR_ECDH 73 #if !defined(MBEDTLS_CONFIG_FILE) 74 #include "mbedtls/config.h" 75 #else 76 #include MBEDTLS_CONFIG_FILE 77 #endif 78 #if defined(MBEDTLS_PLATFORM_C) 79 #include "mbedtls/platform.h" 80 #else 81 #include <stdio.h> 82 #define mbedtls_printf printf 83 #endif 84 #include "mbedtls/ecp.h" 85 #endif 86 87 // 88 // SM internal types and globals 89 // 90 91 typedef enum { 92 DKG_W4_WORKING, 93 DKG_CALC_IRK, 94 DKG_W4_IRK, 95 DKG_CALC_DHK, 96 DKG_W4_DHK, 97 DKG_READY 98 } derived_key_generation_t; 99 100 typedef enum { 101 RAU_W4_WORKING, 102 RAU_IDLE, 103 RAU_GET_RANDOM, 104 RAU_W4_RANDOM, 105 RAU_GET_ENC, 106 RAU_W4_ENC, 107 RAU_SET_ADDRESS, 108 } random_address_update_t; 109 110 typedef enum { 111 CMAC_IDLE, 112 CMAC_CALC_SUBKEYS, 113 CMAC_W4_SUBKEYS, 114 CMAC_CALC_MI, 115 CMAC_W4_MI, 116 CMAC_CALC_MLAST, 117 CMAC_W4_MLAST 118 } cmac_state_t; 119 120 typedef enum { 121 JUST_WORKS, 122 PK_RESP_INPUT, // Initiator displays PK, responder inputs PK 123 PK_INIT_INPUT, // Responder displays PK, initiator inputs PK 124 OK_BOTH_INPUT, // Only input on both, both input PK 125 NK_BOTH_INPUT, // Only numerical compparison (yes/no) on on both sides 126 OOB // OOB available on both sides 127 } stk_generation_method_t; 128 129 typedef enum { 130 SM_USER_RESPONSE_IDLE, 131 SM_USER_RESPONSE_PENDING, 132 SM_USER_RESPONSE_CONFIRM, 133 SM_USER_RESPONSE_PASSKEY, 134 SM_USER_RESPONSE_DECLINE 135 } sm_user_response_t; 136 137 typedef enum { 138 SM_AES128_IDLE, 139 SM_AES128_ACTIVE 140 } sm_aes128_state_t; 141 142 typedef enum { 143 ADDRESS_RESOLUTION_IDLE, 144 ADDRESS_RESOLUTION_GENERAL, 145 ADDRESS_RESOLUTION_FOR_CONNECTION, 146 } address_resolution_mode_t; 147 148 typedef enum { 149 ADDRESS_RESOLUTION_SUCEEDED, 150 ADDRESS_RESOLUTION_FAILED, 151 } address_resolution_event_t; 152 153 typedef enum { 154 EC_KEY_GENERATION_IDLE, 155 EC_KEY_GENERATION_ACTIVE, 156 EC_KEY_GENERATION_DONE, 157 } ec_key_generation_state_t; 158 159 typedef enum { 160 SM_STATE_VAR_DHKEY_COMMAND_RECEIVED = 1 << 0 161 } sm_state_var_t; 162 163 // 164 // GLOBAL DATA 165 // 166 167 static uint8_t test_use_fixed_local_csrk; 168 static uint8_t test_use_fixed_ec_keypair; 169 170 // configuration 171 static uint8_t sm_accepted_stk_generation_methods; 172 static uint8_t sm_max_encryption_key_size; 173 static uint8_t sm_min_encryption_key_size; 174 static uint8_t sm_auth_req = 0; 175 static uint8_t sm_io_capabilities = IO_CAPABILITY_NO_INPUT_NO_OUTPUT; 176 static uint8_t sm_slave_request_security; 177 178 // Security Manager Master Keys, please use sm_set_er(er) and sm_set_ir(ir) with your own 128 bit random values 179 static sm_key_t sm_persistent_er; 180 static sm_key_t sm_persistent_ir; 181 182 // derived from sm_persistent_ir 183 static sm_key_t sm_persistent_dhk; 184 static sm_key_t sm_persistent_irk; 185 static uint8_t sm_persistent_irk_ready = 0; // used for testing 186 static derived_key_generation_t dkg_state; 187 188 // derived from sm_persistent_er 189 // .. 190 191 // random address update 192 static random_address_update_t rau_state; 193 static bd_addr_t sm_random_address; 194 195 // CMAC Calculation: General 196 static cmac_state_t sm_cmac_state; 197 static uint16_t sm_cmac_message_len; 198 static sm_key_t sm_cmac_k; 199 static sm_key_t sm_cmac_x; 200 static sm_key_t sm_cmac_m_last; 201 static uint8_t sm_cmac_block_current; 202 static uint8_t sm_cmac_block_count; 203 static uint8_t (*sm_cmac_get_byte)(uint16_t offset); 204 static void (*sm_cmac_done_handler)(uint8_t * hash); 205 206 // CMAC for ATT Signed Writes 207 static uint8_t sm_cmac_header[3]; 208 static const uint8_t * sm_cmac_message; 209 static uint8_t sm_cmac_sign_counter[4]; 210 211 // CMAC for Secure Connection functions 212 #ifdef ENABLE_LE_SECURE_CONNECTIONS 213 static sm_connection_t * sm_cmac_connection; 214 static uint8_t sm_cmac_sc_buffer[80]; 215 #endif 216 217 // resolvable private address lookup / CSRK calculation 218 static int sm_address_resolution_test; 219 static int sm_address_resolution_ah_calculation_active; 220 static uint8_t sm_address_resolution_addr_type; 221 static bd_addr_t sm_address_resolution_address; 222 static void * sm_address_resolution_context; 223 static address_resolution_mode_t sm_address_resolution_mode; 224 static btstack_linked_list_t sm_address_resolution_general_queue; 225 226 // aes128 crypto engine. store current sm_connection_t in sm_aes128_context 227 static sm_aes128_state_t sm_aes128_state; 228 static void * sm_aes128_context; 229 230 // random engine. store context (ususally sm_connection_t) 231 static void * sm_random_context; 232 233 // to receive hci events 234 static btstack_packet_callback_registration_t hci_event_callback_registration; 235 236 /* to dispatch sm event */ 237 static btstack_linked_list_t sm_event_handlers; 238 239 // Software ECDH implementation provided by mbedtls 240 #ifdef USE_MBEDTLS_FOR_ECDH 241 static mbedtls_ecp_keypair le_keypair; 242 static ec_key_generation_state_t ec_key_generation_state; 243 #endif 244 245 // 246 // Volume 3, Part H, Chapter 24 247 // "Security shall be initiated by the Security Manager in the device in the master role. 248 // The device in the slave role shall be the responding device." 249 // -> master := initiator, slave := responder 250 // 251 252 // data needed for security setup 253 typedef struct sm_setup_context { 254 255 btstack_timer_source_t sm_timeout; 256 257 // used in all phases 258 uint8_t sm_pairing_failed_reason; 259 260 // user response, (Phase 1 and/or 2) 261 uint8_t sm_user_response; 262 263 // defines which keys will be send after connection is encrypted - calculated during Phase 1, used Phase 3 264 int sm_key_distribution_send_set; 265 int sm_key_distribution_received_set; 266 267 // Phase 2 (Pairing over SMP) 268 stk_generation_method_t sm_stk_generation_method; 269 sm_key_t sm_tk; 270 uint8_t sm_use_secure_connections; 271 272 sm_key_t sm_c1_t3_value; // c1 calculation 273 sm_pairing_packet_t sm_m_preq; // pairing request - needed only for c1 274 sm_pairing_packet_t sm_s_pres; // pairing response - needed only for c1 275 sm_key_t sm_local_random; 276 sm_key_t sm_local_confirm; 277 sm_key_t sm_peer_random; 278 sm_key_t sm_peer_confirm; 279 uint8_t sm_m_addr_type; // address and type can be removed 280 uint8_t sm_s_addr_type; // '' 281 bd_addr_t sm_m_address; // '' 282 bd_addr_t sm_s_address; // '' 283 sm_key_t sm_ltk; 284 285 #ifdef ENABLE_LE_SECURE_CONNECTIONS 286 uint8_t sm_peer_qx[32]; // also stores random for EC key generation during init 287 uint8_t sm_peer_qy[32]; // '' 288 sm_key_t sm_peer_nonce; // might be combined with sm_peer_random 289 sm_key_t sm_local_nonce; // might be combined with sm_local_random 290 sm_key_t sm_peer_dhkey_check; 291 sm_key_t sm_local_dhkey_check; 292 sm_key_t sm_ra; 293 sm_key_t sm_rb; 294 sm_key_t sm_t; // used for f5 295 sm_key_t sm_mackey; 296 uint8_t sm_passkey_bit; // also stores number of generated random bytes for EC key generation 297 uint8_t sm_state_vars; 298 #endif 299 300 // Phase 3 301 302 // key distribution, we generate 303 uint16_t sm_local_y; 304 uint16_t sm_local_div; 305 uint16_t sm_local_ediv; 306 uint8_t sm_local_rand[8]; 307 sm_key_t sm_local_ltk; 308 sm_key_t sm_local_csrk; 309 sm_key_t sm_local_irk; 310 // sm_local_address/addr_type not needed 311 312 // key distribution, received from peer 313 uint16_t sm_peer_y; 314 uint16_t sm_peer_div; 315 uint16_t sm_peer_ediv; 316 uint8_t sm_peer_rand[8]; 317 sm_key_t sm_peer_ltk; 318 sm_key_t sm_peer_irk; 319 sm_key_t sm_peer_csrk; 320 uint8_t sm_peer_addr_type; 321 bd_addr_t sm_peer_address; 322 323 } sm_setup_context_t; 324 325 // 326 static sm_setup_context_t the_setup; 327 static sm_setup_context_t * setup = &the_setup; 328 329 // active connection - the one for which the_setup is used for 330 static uint16_t sm_active_connection = 0; 331 332 // @returns 1 if oob data is available 333 // stores oob data in provided 16 byte buffer if not null 334 static int (*sm_get_oob_data)(uint8_t addres_type, bd_addr_t addr, uint8_t * oob_data) = NULL; 335 336 // used to notify applicationss that user interaction is neccessary, see sm_notify_t below 337 static btstack_packet_handler_t sm_client_packet_handler = NULL; 338 339 // horizontal: initiator capabilities 340 // vertial: responder capabilities 341 static const stk_generation_method_t stk_generation_method [5] [5] = { 342 { JUST_WORKS, JUST_WORKS, PK_INIT_INPUT, JUST_WORKS, PK_INIT_INPUT }, 343 { JUST_WORKS, JUST_WORKS, PK_INIT_INPUT, JUST_WORKS, PK_INIT_INPUT }, 344 { PK_RESP_INPUT, PK_RESP_INPUT, OK_BOTH_INPUT, JUST_WORKS, PK_RESP_INPUT }, 345 { JUST_WORKS, JUST_WORKS, JUST_WORKS, JUST_WORKS, JUST_WORKS }, 346 { PK_RESP_INPUT, PK_RESP_INPUT, PK_INIT_INPUT, JUST_WORKS, PK_RESP_INPUT }, 347 }; 348 349 // uses numeric comparison if one side has DisplayYesNo and KeyboardDisplay combinations 350 #ifdef ENABLE_LE_SECURE_CONNECTIONS 351 static const stk_generation_method_t stk_generation_method_with_secure_connection[5][5] = { 352 { JUST_WORKS, JUST_WORKS, PK_INIT_INPUT, JUST_WORKS, PK_INIT_INPUT }, 353 { JUST_WORKS, NK_BOTH_INPUT, PK_INIT_INPUT, JUST_WORKS, NK_BOTH_INPUT }, 354 { PK_RESP_INPUT, PK_RESP_INPUT, OK_BOTH_INPUT, JUST_WORKS, PK_RESP_INPUT }, 355 { JUST_WORKS, JUST_WORKS, JUST_WORKS, JUST_WORKS, JUST_WORKS }, 356 { PK_RESP_INPUT, NK_BOTH_INPUT, PK_INIT_INPUT, JUST_WORKS, NK_BOTH_INPUT }, 357 }; 358 #endif 359 360 static void sm_run(void); 361 static void sm_done_for_handle(hci_con_handle_t con_handle); 362 static sm_connection_t * sm_get_connection_for_handle(hci_con_handle_t con_handle); 363 static inline int sm_calc_actual_encryption_key_size(int other); 364 static int sm_validate_stk_generation_method(void); 365 static void sm_shift_left_by_one_bit_inplace(int len, uint8_t * data); 366 367 static void log_info_hex16(const char * name, uint16_t value){ 368 log_info("%-6s 0x%04x", name, value); 369 } 370 371 // @returns 1 if all bytes are 0 372 static int sm_is_null_random(uint8_t random[8]){ 373 int i; 374 for (i=0; i < 8 ; i++){ 375 if (random[i]) return 0; 376 } 377 return 1; 378 } 379 380 // Key utils 381 static void sm_reset_tk(void){ 382 int i; 383 for (i=0;i<16;i++){ 384 setup->sm_tk[i] = 0; 385 } 386 } 387 388 // "For example, if a 128-bit encryption key is 0x123456789ABCDEF0123456789ABCDEF0 389 // and it is reduced to 7 octets (56 bits), then the resulting key is 0x0000000000000000003456789ABCDEF0."" 390 static void sm_truncate_key(sm_key_t key, int max_encryption_size){ 391 int i; 392 for (i = max_encryption_size ; i < 16 ; i++){ 393 key[15-i] = 0; 394 } 395 } 396 397 // SMP Timeout implementation 398 399 // Upon transmission of the Pairing Request command or reception of the Pairing Request command, 400 // the Security Manager Timer shall be reset and started. 401 // 402 // The Security Manager Timer shall be reset when an L2CAP SMP command is queued for transmission. 403 // 404 // If the Security Manager Timer reaches 30 seconds, the procedure shall be considered to have failed, 405 // and the local higher layer shall be notified. No further SMP commands shall be sent over the L2CAP 406 // Security Manager Channel. A new SM procedure shall only be performed when a new physical link has been 407 // established. 408 409 static void sm_timeout_handler(btstack_timer_source_t * timer){ 410 log_info("SM timeout"); 411 sm_connection_t * sm_conn = (sm_connection_t*) btstack_run_loop_get_timer_context(timer); 412 sm_conn->sm_engine_state = SM_GENERAL_TIMEOUT; 413 sm_done_for_handle(sm_conn->sm_handle); 414 415 // trigger handling of next ready connection 416 sm_run(); 417 } 418 static void sm_timeout_start(sm_connection_t * sm_conn){ 419 btstack_run_loop_remove_timer(&setup->sm_timeout); 420 btstack_run_loop_set_timer_context(&setup->sm_timeout, sm_conn); 421 btstack_run_loop_set_timer_handler(&setup->sm_timeout, sm_timeout_handler); 422 btstack_run_loop_set_timer(&setup->sm_timeout, 30000); // 30 seconds sm timeout 423 btstack_run_loop_add_timer(&setup->sm_timeout); 424 } 425 static void sm_timeout_stop(void){ 426 btstack_run_loop_remove_timer(&setup->sm_timeout); 427 } 428 static void sm_timeout_reset(sm_connection_t * sm_conn){ 429 sm_timeout_stop(); 430 sm_timeout_start(sm_conn); 431 } 432 433 // end of sm timeout 434 435 // GAP Random Address updates 436 static gap_random_address_type_t gap_random_adress_type; 437 static btstack_timer_source_t gap_random_address_update_timer; 438 static uint32_t gap_random_adress_update_period; 439 440 static void gap_random_address_trigger(void){ 441 if (rau_state != RAU_IDLE) return; 442 log_info("gap_random_address_trigger"); 443 rau_state = RAU_GET_RANDOM; 444 sm_run(); 445 } 446 447 static void gap_random_address_update_handler(btstack_timer_source_t * timer){ 448 log_info("GAP Random Address Update due"); 449 btstack_run_loop_set_timer(&gap_random_address_update_timer, gap_random_adress_update_period); 450 btstack_run_loop_add_timer(&gap_random_address_update_timer); 451 gap_random_address_trigger(); 452 } 453 454 static void gap_random_address_update_start(void){ 455 btstack_run_loop_set_timer_handler(&gap_random_address_update_timer, gap_random_address_update_handler); 456 btstack_run_loop_set_timer(&gap_random_address_update_timer, gap_random_adress_update_period); 457 btstack_run_loop_add_timer(&gap_random_address_update_timer); 458 } 459 460 static void gap_random_address_update_stop(void){ 461 btstack_run_loop_remove_timer(&gap_random_address_update_timer); 462 } 463 464 465 static void sm_random_start(void * context){ 466 sm_random_context = context; 467 hci_send_cmd(&hci_le_rand); 468 } 469 470 // pre: sm_aes128_state != SM_AES128_ACTIVE, hci_can_send_command == 1 471 // context is made availabe to aes128 result handler by this 472 static void sm_aes128_start(sm_key_t key, sm_key_t plaintext, void * context){ 473 sm_aes128_state = SM_AES128_ACTIVE; 474 sm_key_t key_flipped, plaintext_flipped; 475 reverse_128(key, key_flipped); 476 reverse_128(plaintext, plaintext_flipped); 477 sm_aes128_context = context; 478 hci_send_cmd(&hci_le_encrypt, key_flipped, plaintext_flipped); 479 } 480 481 // ah(k,r) helper 482 // r = padding || r 483 // r - 24 bit value 484 static void sm_ah_r_prime(uint8_t r[3], sm_key_t r_prime){ 485 // r'= padding || r 486 memset(r_prime, 0, 16); 487 memcpy(&r_prime[13], r, 3); 488 } 489 490 // d1 helper 491 // d' = padding || r || d 492 // d,r - 16 bit values 493 static void sm_d1_d_prime(uint16_t d, uint16_t r, sm_key_t d1_prime){ 494 // d'= padding || r || d 495 memset(d1_prime, 0, 16); 496 big_endian_store_16(d1_prime, 12, r); 497 big_endian_store_16(d1_prime, 14, d); 498 } 499 500 // dm helper 501 // r’ = padding || r 502 // r - 64 bit value 503 static void sm_dm_r_prime(uint8_t r[8], sm_key_t r_prime){ 504 memset(r_prime, 0, 16); 505 memcpy(&r_prime[8], r, 8); 506 } 507 508 // calculate arguments for first AES128 operation in C1 function 509 static void sm_c1_t1(sm_key_t r, uint8_t preq[7], uint8_t pres[7], uint8_t iat, uint8_t rat, sm_key_t t1){ 510 511 // p1 = pres || preq || rat’ || iat’ 512 // "The octet of iat’ becomes the least significant octet of p1 and the most signifi- 513 // cant octet of pres becomes the most significant octet of p1. 514 // For example, if the 8-bit iat’ is 0x01, the 8-bit rat’ is 0x00, the 56-bit preq 515 // is 0x07071000000101 and the 56 bit pres is 0x05000800000302 then 516 // p1 is 0x05000800000302070710000001010001." 517 518 sm_key_t p1; 519 reverse_56(pres, &p1[0]); 520 reverse_56(preq, &p1[7]); 521 p1[14] = rat; 522 p1[15] = iat; 523 log_info_key("p1", p1); 524 log_info_key("r", r); 525 526 // t1 = r xor p1 527 int i; 528 for (i=0;i<16;i++){ 529 t1[i] = r[i] ^ p1[i]; 530 } 531 log_info_key("t1", t1); 532 } 533 534 // calculate arguments for second AES128 operation in C1 function 535 static void sm_c1_t3(sm_key_t t2, bd_addr_t ia, bd_addr_t ra, sm_key_t t3){ 536 // p2 = padding || ia || ra 537 // "The least significant octet of ra becomes the least significant octet of p2 and 538 // the most significant octet of padding becomes the most significant octet of p2. 539 // For example, if 48-bit ia is 0xA1A2A3A4A5A6 and the 48-bit ra is 540 // 0xB1B2B3B4B5B6 then p2 is 0x00000000A1A2A3A4A5A6B1B2B3B4B5B6. 541 542 sm_key_t p2; 543 memset(p2, 0, 16); 544 memcpy(&p2[4], ia, 6); 545 memcpy(&p2[10], ra, 6); 546 log_info_key("p2", p2); 547 548 // c1 = e(k, t2_xor_p2) 549 int i; 550 for (i=0;i<16;i++){ 551 t3[i] = t2[i] ^ p2[i]; 552 } 553 log_info_key("t3", t3); 554 } 555 556 static void sm_s1_r_prime(sm_key_t r1, sm_key_t r2, sm_key_t r_prime){ 557 log_info_key("r1", r1); 558 log_info_key("r2", r2); 559 memcpy(&r_prime[8], &r2[8], 8); 560 memcpy(&r_prime[0], &r1[8], 8); 561 } 562 563 #ifdef ENABLE_LE_SECURE_CONNECTIONS 564 // Software implementations of crypto toolbox for LE Secure Connection 565 // TODO: replace with code to use AES Engine of HCI Controller 566 typedef uint8_t sm_key24_t[3]; 567 typedef uint8_t sm_key56_t[7]; 568 typedef uint8_t sm_key256_t[32]; 569 570 #if 0 571 static void aes128_calc_cyphertext(const uint8_t key[16], const uint8_t plaintext[16], uint8_t cyphertext[16]){ 572 uint32_t rk[RKLENGTH(KEYBITS)]; 573 int nrounds = rijndaelSetupEncrypt(rk, &key[0], KEYBITS); 574 rijndaelEncrypt(rk, nrounds, plaintext, cyphertext); 575 } 576 577 static void calc_subkeys(sm_key_t k0, sm_key_t k1, sm_key_t k2){ 578 memcpy(k1, k0, 16); 579 sm_shift_left_by_one_bit_inplace(16, k1); 580 if (k0[0] & 0x80){ 581 k1[15] ^= 0x87; 582 } 583 memcpy(k2, k1, 16); 584 sm_shift_left_by_one_bit_inplace(16, k2); 585 if (k1[0] & 0x80){ 586 k2[15] ^= 0x87; 587 } 588 } 589 590 static void aes_cmac(sm_key_t aes_cmac, const sm_key_t key, const uint8_t * data, int cmac_message_len){ 591 sm_key_t k0, k1, k2, zero; 592 memset(zero, 0, 16); 593 594 aes128_calc_cyphertext(key, zero, k0); 595 calc_subkeys(k0, k1, k2); 596 597 int cmac_block_count = (cmac_message_len + 15) / 16; 598 599 // step 3: .. 600 if (cmac_block_count==0){ 601 cmac_block_count = 1; 602 } 603 604 // step 4: set m_last 605 sm_key_t cmac_m_last; 606 int sm_cmac_last_block_complete = cmac_message_len != 0 && (cmac_message_len & 0x0f) == 0; 607 int i; 608 if (sm_cmac_last_block_complete){ 609 for (i=0;i<16;i++){ 610 cmac_m_last[i] = data[cmac_message_len - 16 + i] ^ k1[i]; 611 } 612 } else { 613 int valid_octets_in_last_block = cmac_message_len & 0x0f; 614 for (i=0;i<16;i++){ 615 if (i < valid_octets_in_last_block){ 616 cmac_m_last[i] = data[(cmac_message_len & 0xfff0) + i] ^ k2[i]; 617 continue; 618 } 619 if (i == valid_octets_in_last_block){ 620 cmac_m_last[i] = 0x80 ^ k2[i]; 621 continue; 622 } 623 cmac_m_last[i] = k2[i]; 624 } 625 } 626 627 // printf("sm_cmac_start: len %u, block count %u\n", cmac_message_len, cmac_block_count); 628 // LOG_KEY(cmac_m_last); 629 630 // Step 5 631 sm_key_t cmac_x; 632 memset(cmac_x, 0, 16); 633 634 // Step 6 635 sm_key_t sm_cmac_y; 636 for (int block = 0 ; block < cmac_block_count-1 ; block++){ 637 for (i=0;i<16;i++){ 638 sm_cmac_y[i] = cmac_x[i] ^ data[block * 16 + i]; 639 } 640 aes128_calc_cyphertext(key, sm_cmac_y, cmac_x); 641 } 642 for (i=0;i<16;i++){ 643 sm_cmac_y[i] = cmac_x[i] ^ cmac_m_last[i]; 644 } 645 646 // Step 7 647 aes128_calc_cyphertext(key, sm_cmac_y, aes_cmac); 648 } 649 #endif 650 651 #if 0 652 // 653 // Link Key Conversion Function h6 654 // 655 // h6(W, keyID) = AES-CMACW(keyID) 656 // - W is 128 bits 657 // - keyID is 32 bits 658 static void h6(sm_key_t res, const sm_key_t w, const uint32_t key_id){ 659 uint8_t key_id_buffer[4]; 660 big_endian_store_32(key_id_buffer, 0, key_id); 661 aes_cmac(res, w, key_id_buffer, 4); 662 } 663 #endif 664 #endif 665 666 static void sm_setup_event_base(uint8_t * event, int event_size, uint8_t type, hci_con_handle_t con_handle, uint8_t addr_type, bd_addr_t address){ 667 event[0] = type; 668 event[1] = event_size - 2; 669 little_endian_store_16(event, 2, con_handle); 670 event[4] = addr_type; 671 reverse_bd_addr(address, &event[5]); 672 } 673 674 static void sm_dispatch_event(uint8_t packet_type, uint16_t channel, uint8_t * packet, uint16_t size){ 675 if (sm_client_packet_handler) { 676 sm_client_packet_handler(HCI_EVENT_PACKET, 0, packet, size); 677 } 678 // dispatch to all event handlers 679 btstack_linked_list_iterator_t it; 680 btstack_linked_list_iterator_init(&it, &sm_event_handlers); 681 while (btstack_linked_list_iterator_has_next(&it)){ 682 btstack_packet_callback_registration_t * entry = (btstack_packet_callback_registration_t*) btstack_linked_list_iterator_next(&it); 683 entry->callback(packet_type, 0, packet, size); 684 } 685 } 686 687 static void sm_notify_client_base(uint8_t type, hci_con_handle_t con_handle, uint8_t addr_type, bd_addr_t address){ 688 uint8_t event[11]; 689 sm_setup_event_base(event, sizeof(event), type, con_handle, addr_type, address); 690 sm_dispatch_event(HCI_EVENT_PACKET, 0, event, sizeof(event)); 691 } 692 693 static void sm_notify_client_passkey(uint8_t type, hci_con_handle_t con_handle, uint8_t addr_type, bd_addr_t address, uint32_t passkey){ 694 uint8_t event[15]; 695 sm_setup_event_base(event, sizeof(event), type, con_handle, addr_type, address); 696 little_endian_store_32(event, 11, passkey); 697 sm_dispatch_event(HCI_EVENT_PACKET, 0, event, sizeof(event)); 698 } 699 700 static void sm_notify_client_index(uint8_t type, hci_con_handle_t con_handle, uint8_t addr_type, bd_addr_t address, uint16_t index){ 701 uint8_t event[13]; 702 sm_setup_event_base(event, sizeof(event), type, con_handle, addr_type, address); 703 little_endian_store_16(event, 11, index); 704 sm_dispatch_event(HCI_EVENT_PACKET, 0, event, sizeof(event)); 705 } 706 707 static void sm_notify_client_authorization(uint8_t type, hci_con_handle_t con_handle, uint8_t addr_type, bd_addr_t address, uint8_t result){ 708 709 uint8_t event[18]; 710 sm_setup_event_base(event, sizeof(event), type, con_handle, addr_type, address); 711 event[11] = result; 712 sm_dispatch_event(HCI_EVENT_PACKET, 0, (uint8_t*) &event, sizeof(event)); 713 } 714 715 // decide on stk generation based on 716 // - pairing request 717 // - io capabilities 718 // - OOB data availability 719 static void sm_setup_tk(void){ 720 721 // default: just works 722 setup->sm_stk_generation_method = JUST_WORKS; 723 724 #ifdef ENABLE_LE_SECURE_CONNECTIONS 725 setup->sm_use_secure_connections = ( sm_pairing_packet_get_auth_req(setup->sm_m_preq) 726 & sm_pairing_packet_get_auth_req(setup->sm_s_pres) 727 & SM_AUTHREQ_SECURE_CONNECTION ) != 0; 728 memset(setup->sm_ra, 0, 16); 729 memset(setup->sm_rb, 0, 16); 730 #else 731 setup->sm_use_secure_connections = 0; 732 #endif 733 734 // If both devices have not set the MITM option in the Authentication Requirements 735 // Flags, then the IO capabilities shall be ignored and the Just Works association 736 // model shall be used. 737 if (((sm_pairing_packet_get_auth_req(setup->sm_m_preq) & SM_AUTHREQ_MITM_PROTECTION) == 0) 738 && ((sm_pairing_packet_get_auth_req(setup->sm_s_pres) & SM_AUTHREQ_MITM_PROTECTION) == 0)){ 739 log_info("SM: MITM not required by both -> JUST WORKS"); 740 return; 741 } 742 743 // TODO: with LE SC, OOB is used to transfer data OOB during pairing, single device with OOB is sufficient 744 745 // If both devices have out of band authentication data, then the Authentication 746 // Requirements Flags shall be ignored when selecting the pairing method and the 747 // Out of Band pairing method shall be used. 748 if (sm_pairing_packet_get_oob_data_flag(setup->sm_m_preq) 749 && sm_pairing_packet_get_oob_data_flag(setup->sm_s_pres)){ 750 log_info("SM: have OOB data"); 751 log_info_key("OOB", setup->sm_tk); 752 setup->sm_stk_generation_method = OOB; 753 return; 754 } 755 756 // Reset TK as it has been setup in sm_init_setup 757 sm_reset_tk(); 758 759 // Also use just works if unknown io capabilites 760 if ((sm_pairing_packet_get_io_capability(setup->sm_m_preq) > IO_CAPABILITY_KEYBOARD_DISPLAY) || (sm_pairing_packet_get_io_capability(setup->sm_s_pres) > IO_CAPABILITY_KEYBOARD_DISPLAY)){ 761 return; 762 } 763 764 // Otherwise the IO capabilities of the devices shall be used to determine the 765 // pairing method as defined in Table 2.4. 766 // see http://stackoverflow.com/a/1052837/393697 for how to specify pointer to 2-dimensional array 767 const stk_generation_method_t (*generation_method)[5] = stk_generation_method; 768 769 #ifdef ENABLE_LE_SECURE_CONNECTIONS 770 // table not define by default 771 if (setup->sm_use_secure_connections){ 772 generation_method = stk_generation_method_with_secure_connection; 773 } 774 #endif 775 setup->sm_stk_generation_method = generation_method[sm_pairing_packet_get_io_capability(setup->sm_s_pres)][sm_pairing_packet_get_io_capability(setup->sm_m_preq)]; 776 777 log_info("sm_setup_tk: master io cap: %u, slave io cap: %u -> method %u", 778 sm_pairing_packet_get_io_capability(setup->sm_m_preq), sm_pairing_packet_get_io_capability(setup->sm_s_pres), setup->sm_stk_generation_method); 779 } 780 781 static int sm_key_distribution_flags_for_set(uint8_t key_set){ 782 int flags = 0; 783 if (key_set & SM_KEYDIST_ENC_KEY){ 784 flags |= SM_KEYDIST_FLAG_ENCRYPTION_INFORMATION; 785 flags |= SM_KEYDIST_FLAG_MASTER_IDENTIFICATION; 786 } 787 if (key_set & SM_KEYDIST_ID_KEY){ 788 flags |= SM_KEYDIST_FLAG_IDENTITY_INFORMATION; 789 flags |= SM_KEYDIST_FLAG_IDENTITY_ADDRESS_INFORMATION; 790 } 791 if (key_set & SM_KEYDIST_SIGN){ 792 flags |= SM_KEYDIST_FLAG_SIGNING_IDENTIFICATION; 793 } 794 return flags; 795 } 796 797 static void sm_setup_key_distribution(uint8_t key_set){ 798 setup->sm_key_distribution_received_set = 0; 799 setup->sm_key_distribution_send_set = sm_key_distribution_flags_for_set(key_set); 800 } 801 802 // CSRK Key Lookup 803 804 805 static int sm_address_resolution_idle(void){ 806 return sm_address_resolution_mode == ADDRESS_RESOLUTION_IDLE; 807 } 808 809 static void sm_address_resolution_start_lookup(uint8_t addr_type, hci_con_handle_t con_handle, bd_addr_t addr, address_resolution_mode_t mode, void * context){ 810 memcpy(sm_address_resolution_address, addr, 6); 811 sm_address_resolution_addr_type = addr_type; 812 sm_address_resolution_test = 0; 813 sm_address_resolution_mode = mode; 814 sm_address_resolution_context = context; 815 sm_notify_client_base(SM_EVENT_IDENTITY_RESOLVING_STARTED, con_handle, addr_type, addr); 816 } 817 818 int sm_address_resolution_lookup(uint8_t address_type, bd_addr_t address){ 819 // check if already in list 820 btstack_linked_list_iterator_t it; 821 sm_lookup_entry_t * entry; 822 btstack_linked_list_iterator_init(&it, &sm_address_resolution_general_queue); 823 while(btstack_linked_list_iterator_has_next(&it)){ 824 entry = (sm_lookup_entry_t *) btstack_linked_list_iterator_next(&it); 825 if (entry->address_type != address_type) continue; 826 if (memcmp(entry->address, address, 6)) continue; 827 // already in list 828 return BTSTACK_BUSY; 829 } 830 entry = btstack_memory_sm_lookup_entry_get(); 831 if (!entry) return BTSTACK_MEMORY_ALLOC_FAILED; 832 entry->address_type = (bd_addr_type_t) address_type; 833 memcpy(entry->address, address, 6); 834 btstack_linked_list_add(&sm_address_resolution_general_queue, (btstack_linked_item_t *) entry); 835 sm_run(); 836 return 0; 837 } 838 839 // CMAC Implementation using AES128 engine 840 static void sm_shift_left_by_one_bit_inplace(int len, uint8_t * data){ 841 int i; 842 int carry = 0; 843 for (i=len-1; i >= 0 ; i--){ 844 int new_carry = data[i] >> 7; 845 data[i] = data[i] << 1 | carry; 846 carry = new_carry; 847 } 848 } 849 850 // while x_state++ for an enum is possible in C, it isn't in C++. we use this helpers to avoid compile errors for now 851 static inline void sm_next_responding_state(sm_connection_t * sm_conn){ 852 sm_conn->sm_engine_state = (security_manager_state_t) (((int)sm_conn->sm_engine_state) + 1); 853 } 854 static inline void dkg_next_state(void){ 855 dkg_state = (derived_key_generation_t) (((int)dkg_state) + 1); 856 } 857 static inline void rau_next_state(void){ 858 rau_state = (random_address_update_t) (((int)rau_state) + 1); 859 } 860 861 // CMAC calculation using AES Engine 862 863 static inline void sm_cmac_next_state(void){ 864 sm_cmac_state = (cmac_state_t) (((int)sm_cmac_state) + 1); 865 } 866 867 static int sm_cmac_last_block_complete(void){ 868 if (sm_cmac_message_len == 0) return 0; 869 return (sm_cmac_message_len & 0x0f) == 0; 870 } 871 872 static inline uint8_t sm_cmac_message_get_byte(uint16_t offset){ 873 if (offset >= sm_cmac_message_len) { 874 log_error("sm_cmac_message_get_byte. out of bounds, access %u, len %u", offset, sm_cmac_message_len); 875 return 0; 876 } 877 878 offset = sm_cmac_message_len - 1 - offset; 879 880 // sm_cmac_header[3] | message[] | sm_cmac_sign_counter[4] 881 if (offset < 3){ 882 return sm_cmac_header[offset]; 883 } 884 int actual_message_len_incl_header = sm_cmac_message_len - 4; 885 if (offset < actual_message_len_incl_header){ 886 return sm_cmac_message[offset - 3]; 887 } 888 return sm_cmac_sign_counter[offset - actual_message_len_incl_header]; 889 } 890 891 // generic cmac calculation 892 void sm_cmac_general_start(const sm_key_t key, uint16_t message_len, uint8_t (*get_byte_callback)(uint16_t offset), void (*done_callback)(uint8_t hash[8])){ 893 // Generalized CMAC 894 memcpy(sm_cmac_k, key, 16); 895 memset(sm_cmac_x, 0, 16); 896 sm_cmac_block_current = 0; 897 sm_cmac_message_len = message_len; 898 sm_cmac_done_handler = done_callback; 899 sm_cmac_get_byte = get_byte_callback; 900 901 // step 2: n := ceil(len/const_Bsize); 902 sm_cmac_block_count = (sm_cmac_message_len + 15) / 16; 903 904 // step 3: .. 905 if (sm_cmac_block_count==0){ 906 sm_cmac_block_count = 1; 907 } 908 log_info("sm_cmac_connection %p", sm_cmac_connection); 909 log_info("sm_cmac_general_start: len %u, block count %u", sm_cmac_message_len, sm_cmac_block_count); 910 911 // first, we need to compute l for k1, k2, and m_last 912 sm_cmac_state = CMAC_CALC_SUBKEYS; 913 914 // let's go 915 sm_run(); 916 } 917 918 // cmac for ATT Message signing 919 void sm_cmac_start(const sm_key_t k, uint8_t opcode, hci_con_handle_t con_handle, uint16_t message_len, const uint8_t * message, uint32_t sign_counter, void (*done_handler)(uint8_t * hash)){ 920 // ATT Message Signing 921 sm_cmac_header[0] = opcode; 922 little_endian_store_16(sm_cmac_header, 1, con_handle); 923 little_endian_store_32(sm_cmac_sign_counter, 0, sign_counter); 924 uint16_t total_message_len = 3 + message_len + 4; // incl. virtually prepended att opcode, handle and appended sign_counter in LE 925 sm_cmac_message = message; 926 sm_cmac_general_start(k, total_message_len, &sm_cmac_message_get_byte, done_handler); 927 } 928 929 int sm_cmac_ready(void){ 930 return sm_cmac_state == CMAC_IDLE; 931 } 932 933 static void sm_cmac_handle_aes_engine_ready(void){ 934 switch (sm_cmac_state){ 935 case CMAC_CALC_SUBKEYS: { 936 sm_key_t const_zero; 937 memset(const_zero, 0, 16); 938 sm_cmac_next_state(); 939 sm_aes128_start(sm_cmac_k, const_zero, NULL); 940 break; 941 } 942 case CMAC_CALC_MI: { 943 int j; 944 sm_key_t y; 945 for (j=0;j<16;j++){ 946 y[j] = sm_cmac_x[j] ^ sm_cmac_get_byte(sm_cmac_block_current*16 + j); 947 } 948 sm_cmac_block_current++; 949 sm_cmac_next_state(); 950 sm_aes128_start(sm_cmac_k, y, NULL); 951 break; 952 } 953 case CMAC_CALC_MLAST: { 954 int i; 955 sm_key_t y; 956 for (i=0;i<16;i++){ 957 y[i] = sm_cmac_x[i] ^ sm_cmac_m_last[i]; 958 } 959 log_info_key("Y", y); 960 sm_cmac_block_current++; 961 sm_cmac_next_state(); 962 sm_aes128_start(sm_cmac_k, y, NULL); 963 break; 964 } 965 default: 966 log_info("sm_cmac_handle_aes_engine_ready called in state %u", sm_cmac_state); 967 break; 968 } 969 } 970 971 static void sm_cmac_handle_encryption_result(sm_key_t data){ 972 switch (sm_cmac_state){ 973 case CMAC_W4_SUBKEYS: { 974 sm_key_t k1; 975 memcpy(k1, data, 16); 976 sm_shift_left_by_one_bit_inplace(16, k1); 977 if (data[0] & 0x80){ 978 k1[15] ^= 0x87; 979 } 980 sm_key_t k2; 981 memcpy(k2, k1, 16); 982 sm_shift_left_by_one_bit_inplace(16, k2); 983 if (k1[0] & 0x80){ 984 k2[15] ^= 0x87; 985 } 986 987 log_info_key("k", sm_cmac_k); 988 log_info_key("k1", k1); 989 log_info_key("k2", k2); 990 991 // step 4: set m_last 992 int i; 993 if (sm_cmac_last_block_complete()){ 994 for (i=0;i<16;i++){ 995 sm_cmac_m_last[i] = sm_cmac_get_byte(sm_cmac_message_len - 16 + i) ^ k1[i]; 996 } 997 } else { 998 int valid_octets_in_last_block = sm_cmac_message_len & 0x0f; 999 for (i=0;i<16;i++){ 1000 if (i < valid_octets_in_last_block){ 1001 sm_cmac_m_last[i] = sm_cmac_get_byte((sm_cmac_message_len & 0xfff0) + i) ^ k2[i]; 1002 continue; 1003 } 1004 if (i == valid_octets_in_last_block){ 1005 sm_cmac_m_last[i] = 0x80 ^ k2[i]; 1006 continue; 1007 } 1008 sm_cmac_m_last[i] = k2[i]; 1009 } 1010 } 1011 1012 // next 1013 sm_cmac_state = sm_cmac_block_current < sm_cmac_block_count - 1 ? CMAC_CALC_MI : CMAC_CALC_MLAST; 1014 break; 1015 } 1016 case CMAC_W4_MI: 1017 memcpy(sm_cmac_x, data, 16); 1018 sm_cmac_state = sm_cmac_block_current < sm_cmac_block_count - 1 ? CMAC_CALC_MI : CMAC_CALC_MLAST; 1019 break; 1020 case CMAC_W4_MLAST: 1021 // done 1022 log_info("Setting CMAC Engine to IDLE"); 1023 sm_cmac_state = CMAC_IDLE; 1024 log_info_key("CMAC", data); 1025 sm_cmac_done_handler(data); 1026 break; 1027 default: 1028 log_info("sm_cmac_handle_encryption_result called in state %u", sm_cmac_state); 1029 break; 1030 } 1031 } 1032 1033 static void sm_trigger_user_response(sm_connection_t * sm_conn){ 1034 // notify client for: JUST WORKS confirm, Numeric comparison confirm, PASSKEY display or input 1035 setup->sm_user_response = SM_USER_RESPONSE_IDLE; 1036 switch (setup->sm_stk_generation_method){ 1037 case PK_RESP_INPUT: 1038 if (sm_conn->sm_role){ 1039 setup->sm_user_response = SM_USER_RESPONSE_PENDING; 1040 sm_notify_client_base(SM_EVENT_PASSKEY_INPUT_NUMBER, sm_conn->sm_handle, sm_conn->sm_peer_addr_type, sm_conn->sm_peer_address); 1041 } else { 1042 sm_notify_client_passkey(SM_EVENT_PASSKEY_DISPLAY_NUMBER, sm_conn->sm_handle, sm_conn->sm_peer_addr_type, sm_conn->sm_peer_address, big_endian_read_32(setup->sm_tk, 12)); 1043 } 1044 break; 1045 case PK_INIT_INPUT: 1046 if (sm_conn->sm_role){ 1047 sm_notify_client_passkey(SM_EVENT_PASSKEY_DISPLAY_NUMBER, sm_conn->sm_handle, sm_conn->sm_peer_addr_type, sm_conn->sm_peer_address, big_endian_read_32(setup->sm_tk, 12)); 1048 } else { 1049 setup->sm_user_response = SM_USER_RESPONSE_PENDING; 1050 sm_notify_client_base(SM_EVENT_PASSKEY_INPUT_NUMBER, sm_conn->sm_handle, sm_conn->sm_peer_addr_type, sm_conn->sm_peer_address); 1051 } 1052 break; 1053 case OK_BOTH_INPUT: 1054 setup->sm_user_response = SM_USER_RESPONSE_PENDING; 1055 sm_notify_client_base(SM_EVENT_PASSKEY_INPUT_NUMBER, sm_conn->sm_handle, sm_conn->sm_peer_addr_type, sm_conn->sm_peer_address); 1056 break; 1057 case NK_BOTH_INPUT: 1058 setup->sm_user_response = SM_USER_RESPONSE_PENDING; 1059 sm_notify_client_passkey(SM_EVENT_NUMERIC_COMPARISON_REQUEST, sm_conn->sm_handle, sm_conn->sm_peer_addr_type, sm_conn->sm_peer_address, big_endian_read_32(setup->sm_tk, 12)); 1060 break; 1061 case JUST_WORKS: 1062 setup->sm_user_response = SM_USER_RESPONSE_PENDING; 1063 sm_notify_client_base(SM_EVENT_JUST_WORKS_REQUEST, sm_conn->sm_handle, sm_conn->sm_peer_addr_type, sm_conn->sm_peer_address); 1064 break; 1065 case OOB: 1066 // client already provided OOB data, let's skip notification. 1067 break; 1068 } 1069 } 1070 1071 static int sm_key_distribution_all_received(sm_connection_t * sm_conn){ 1072 int recv_flags; 1073 if (sm_conn->sm_role){ 1074 // slave / responder 1075 recv_flags = sm_key_distribution_flags_for_set(sm_pairing_packet_get_initiator_key_distribution(setup->sm_s_pres)); 1076 } else { 1077 // master / initiator 1078 recv_flags = sm_key_distribution_flags_for_set(sm_pairing_packet_get_responder_key_distribution(setup->sm_s_pres)); 1079 } 1080 log_debug("sm_key_distribution_all_received: received 0x%02x, expecting 0x%02x", setup->sm_key_distribution_received_set, recv_flags); 1081 return recv_flags == setup->sm_key_distribution_received_set; 1082 } 1083 1084 static void sm_done_for_handle(hci_con_handle_t con_handle){ 1085 if (sm_active_connection == con_handle){ 1086 sm_timeout_stop(); 1087 sm_active_connection = 0; 1088 log_info("sm: connection 0x%x released setup context", con_handle); 1089 } 1090 } 1091 1092 static int sm_key_distribution_flags_for_auth_req(void){ 1093 int flags = SM_KEYDIST_ID_KEY | SM_KEYDIST_SIGN; 1094 if (sm_auth_req & SM_AUTHREQ_BONDING){ 1095 // encryption information only if bonding requested 1096 flags |= SM_KEYDIST_ENC_KEY; 1097 } 1098 return flags; 1099 } 1100 1101 static void sm_init_setup(sm_connection_t * sm_conn){ 1102 1103 // fill in sm setup 1104 setup->sm_state_vars = 0; 1105 sm_reset_tk(); 1106 setup->sm_peer_addr_type = sm_conn->sm_peer_addr_type; 1107 memcpy(setup->sm_peer_address, sm_conn->sm_peer_address, 6); 1108 1109 // query client for OOB data 1110 int have_oob_data = 0; 1111 if (sm_get_oob_data) { 1112 have_oob_data = (*sm_get_oob_data)(sm_conn->sm_peer_addr_type, sm_conn->sm_peer_address, setup->sm_tk); 1113 } 1114 1115 sm_pairing_packet_t * local_packet; 1116 if (sm_conn->sm_role){ 1117 // slave 1118 local_packet = &setup->sm_s_pres; 1119 gap_advertisements_get_address(&setup->sm_s_addr_type, setup->sm_s_address); 1120 setup->sm_m_addr_type = sm_conn->sm_peer_addr_type; 1121 memcpy(setup->sm_m_address, sm_conn->sm_peer_address, 6); 1122 } else { 1123 // master 1124 local_packet = &setup->sm_m_preq; 1125 gap_advertisements_get_address(&setup->sm_m_addr_type, setup->sm_m_address); 1126 setup->sm_s_addr_type = sm_conn->sm_peer_addr_type; 1127 memcpy(setup->sm_s_address, sm_conn->sm_peer_address, 6); 1128 1129 int key_distribution_flags = sm_key_distribution_flags_for_auth_req(); 1130 sm_pairing_packet_set_initiator_key_distribution(setup->sm_m_preq, key_distribution_flags); 1131 sm_pairing_packet_set_responder_key_distribution(setup->sm_m_preq, key_distribution_flags); 1132 } 1133 1134 sm_pairing_packet_set_io_capability(*local_packet, sm_io_capabilities); 1135 sm_pairing_packet_set_oob_data_flag(*local_packet, have_oob_data); 1136 sm_pairing_packet_set_auth_req(*local_packet, sm_auth_req); 1137 sm_pairing_packet_set_max_encryption_key_size(*local_packet, sm_max_encryption_key_size); 1138 } 1139 1140 static int sm_stk_generation_init(sm_connection_t * sm_conn){ 1141 1142 sm_pairing_packet_t * remote_packet; 1143 int remote_key_request; 1144 if (sm_conn->sm_role){ 1145 // slave / responder 1146 remote_packet = &setup->sm_m_preq; 1147 remote_key_request = sm_pairing_packet_get_responder_key_distribution(setup->sm_m_preq); 1148 } else { 1149 // master / initiator 1150 remote_packet = &setup->sm_s_pres; 1151 remote_key_request = sm_pairing_packet_get_initiator_key_distribution(setup->sm_s_pres); 1152 } 1153 1154 // check key size 1155 sm_conn->sm_actual_encryption_key_size = sm_calc_actual_encryption_key_size(sm_pairing_packet_get_max_encryption_key_size(*remote_packet)); 1156 if (sm_conn->sm_actual_encryption_key_size == 0) return SM_REASON_ENCRYPTION_KEY_SIZE; 1157 1158 // decide on STK generation method 1159 sm_setup_tk(); 1160 log_info("SMP: generation method %u", setup->sm_stk_generation_method); 1161 1162 // check if STK generation method is acceptable by client 1163 if (!sm_validate_stk_generation_method()) return SM_REASON_AUTHENTHICATION_REQUIREMENTS; 1164 1165 // identical to responder 1166 sm_setup_key_distribution(remote_key_request); 1167 1168 // JUST WORKS doens't provide authentication 1169 sm_conn->sm_connection_authenticated = setup->sm_stk_generation_method == JUST_WORKS ? 0 : 1; 1170 1171 return 0; 1172 } 1173 1174 static void sm_address_resolution_handle_event(address_resolution_event_t event){ 1175 1176 // cache and reset context 1177 int matched_device_id = sm_address_resolution_test; 1178 address_resolution_mode_t mode = sm_address_resolution_mode; 1179 void * context = sm_address_resolution_context; 1180 1181 // reset context 1182 sm_address_resolution_mode = ADDRESS_RESOLUTION_IDLE; 1183 sm_address_resolution_context = NULL; 1184 sm_address_resolution_test = -1; 1185 hci_con_handle_t con_handle = 0; 1186 1187 sm_connection_t * sm_connection; 1188 uint16_t ediv; 1189 switch (mode){ 1190 case ADDRESS_RESOLUTION_GENERAL: 1191 break; 1192 case ADDRESS_RESOLUTION_FOR_CONNECTION: 1193 sm_connection = (sm_connection_t *) context; 1194 con_handle = sm_connection->sm_handle; 1195 switch (event){ 1196 case ADDRESS_RESOLUTION_SUCEEDED: 1197 sm_connection->sm_irk_lookup_state = IRK_LOOKUP_SUCCEEDED; 1198 sm_connection->sm_le_db_index = matched_device_id; 1199 log_info("ADDRESS_RESOLUTION_SUCEEDED, index %d", sm_connection->sm_le_db_index); 1200 if (sm_connection->sm_role) break; 1201 if (!sm_connection->sm_bonding_requested && !sm_connection->sm_security_request_received) break; 1202 sm_connection->sm_security_request_received = 0; 1203 sm_connection->sm_bonding_requested = 0; 1204 le_device_db_encryption_get(sm_connection->sm_le_db_index, &ediv, NULL, NULL, NULL, NULL, NULL); 1205 if (ediv){ 1206 sm_connection->sm_engine_state = SM_INITIATOR_PH0_HAS_LTK; 1207 } else { 1208 sm_connection->sm_engine_state = SM_INITIATOR_PH1_W2_SEND_PAIRING_REQUEST; 1209 } 1210 break; 1211 case ADDRESS_RESOLUTION_FAILED: 1212 sm_connection->sm_irk_lookup_state = IRK_LOOKUP_FAILED; 1213 if (sm_connection->sm_role) break; 1214 if (!sm_connection->sm_bonding_requested && !sm_connection->sm_security_request_received) break; 1215 sm_connection->sm_security_request_received = 0; 1216 sm_connection->sm_bonding_requested = 0; 1217 sm_connection->sm_engine_state = SM_INITIATOR_PH1_W2_SEND_PAIRING_REQUEST; 1218 break; 1219 } 1220 break; 1221 default: 1222 break; 1223 } 1224 1225 switch (event){ 1226 case ADDRESS_RESOLUTION_SUCEEDED: 1227 sm_notify_client_index(SM_EVENT_IDENTITY_RESOLVING_SUCCEEDED, con_handle, sm_address_resolution_addr_type, sm_address_resolution_address, matched_device_id); 1228 break; 1229 case ADDRESS_RESOLUTION_FAILED: 1230 sm_notify_client_base(SM_EVENT_IDENTITY_RESOLVING_FAILED, con_handle, sm_address_resolution_addr_type, sm_address_resolution_address); 1231 break; 1232 } 1233 } 1234 1235 static void sm_key_distribution_handle_all_received(sm_connection_t * sm_conn){ 1236 1237 int le_db_index = -1; 1238 1239 // lookup device based on IRK 1240 if (setup->sm_key_distribution_received_set & SM_KEYDIST_FLAG_IDENTITY_INFORMATION){ 1241 int i; 1242 for (i=0; i < le_device_db_count(); i++){ 1243 sm_key_t irk; 1244 bd_addr_t address; 1245 int address_type; 1246 le_device_db_info(i, &address_type, address, irk); 1247 if (memcmp(irk, setup->sm_peer_irk, 16) == 0){ 1248 log_info("sm: device found for IRK, updating"); 1249 le_db_index = i; 1250 break; 1251 } 1252 } 1253 } 1254 1255 // if not found, lookup via public address if possible 1256 log_info("sm peer addr type %u, peer addres %s", setup->sm_peer_addr_type, bd_addr_to_str(setup->sm_peer_address)); 1257 if (le_db_index < 0 && setup->sm_peer_addr_type == BD_ADDR_TYPE_LE_PUBLIC){ 1258 int i; 1259 for (i=0; i < le_device_db_count(); i++){ 1260 bd_addr_t address; 1261 int address_type; 1262 le_device_db_info(i, &address_type, address, NULL); 1263 log_info("device %u, sm peer addr type %u, peer addres %s", i, address_type, bd_addr_to_str(address)); 1264 if (address_type == BD_ADDR_TYPE_LE_PUBLIC && memcmp(address, setup->sm_peer_address, 6) == 0){ 1265 log_info("sm: device found for public address, updating"); 1266 le_db_index = i; 1267 break; 1268 } 1269 } 1270 } 1271 1272 // if not found, add to db 1273 if (le_db_index < 0) { 1274 le_db_index = le_device_db_add(setup->sm_peer_addr_type, setup->sm_peer_address, setup->sm_peer_irk); 1275 } 1276 1277 if (le_db_index >= 0){ 1278 le_device_db_local_counter_set(le_db_index, 0); 1279 1280 // store local CSRK 1281 if (setup->sm_key_distribution_send_set & SM_KEYDIST_FLAG_SIGNING_IDENTIFICATION){ 1282 log_info("sm: store local CSRK"); 1283 le_device_db_local_csrk_set(le_db_index, setup->sm_local_csrk); 1284 le_device_db_local_counter_set(le_db_index, 0); 1285 } 1286 1287 // store remote CSRK 1288 if (setup->sm_key_distribution_received_set & SM_KEYDIST_FLAG_SIGNING_IDENTIFICATION){ 1289 log_info("sm: store remote CSRK"); 1290 le_device_db_remote_csrk_set(le_db_index, setup->sm_peer_csrk); 1291 le_device_db_remote_counter_set(le_db_index, 0); 1292 } 1293 1294 // store encryption information 1295 if (setup->sm_key_distribution_received_set & SM_KEYDIST_FLAG_ENCRYPTION_INFORMATION 1296 && setup->sm_key_distribution_received_set & SM_KEYDIST_FLAG_MASTER_IDENTIFICATION){ 1297 log_info("sm: set encryption information (key size %u, authenticatd %u)", sm_conn->sm_actual_encryption_key_size, sm_conn->sm_connection_authenticated); 1298 le_device_db_encryption_set(le_db_index, setup->sm_peer_ediv, setup->sm_peer_rand, setup->sm_peer_ltk, 1299 sm_conn->sm_actual_encryption_key_size, sm_conn->sm_connection_authenticated, sm_conn->sm_connection_authorization_state == AUTHORIZATION_GRANTED); 1300 } 1301 } 1302 1303 // keep le_db_index 1304 sm_conn->sm_le_db_index = le_db_index; 1305 } 1306 1307 static void sm_pairing_error(sm_connection_t * sm_conn, uint8_t reason){ 1308 setup->sm_pairing_failed_reason = reason; 1309 sm_conn->sm_engine_state = SM_GENERAL_SEND_PAIRING_FAILED; 1310 } 1311 1312 static inline void sm_pdu_received_in_wrong_state(sm_connection_t * sm_conn){ 1313 sm_pairing_error(sm_conn, SM_REASON_UNSPECIFIED_REASON); 1314 } 1315 1316 #ifdef ENABLE_LE_SECURE_CONNECTIONS 1317 1318 static void sm_sc_prepare_dhkey_check(sm_connection_t * sm_conn); 1319 static int sm_passkey_used(stk_generation_method_t method); 1320 static int sm_just_works_or_numeric_comparison(stk_generation_method_t method); 1321 1322 static void sm_sc_start_calculating_local_confirm(sm_connection_t * sm_conn){ 1323 if (sm_passkey_used(setup->sm_stk_generation_method)){ 1324 sm_conn->sm_engine_state = SM_SC_W2_GET_RANDOM_A; 1325 } else { 1326 sm_conn->sm_engine_state = SM_SC_W2_CMAC_FOR_CONFIRMATION; 1327 } 1328 } 1329 1330 static void sm_sc_state_after_receiving_random(sm_connection_t * sm_conn){ 1331 if (sm_conn->sm_role){ 1332 // Responder 1333 sm_conn->sm_engine_state = SM_SC_SEND_PAIRING_RANDOM; 1334 } else { 1335 // Initiator role 1336 switch (setup->sm_stk_generation_method){ 1337 case JUST_WORKS: 1338 sm_sc_prepare_dhkey_check(sm_conn); 1339 break; 1340 1341 case NK_BOTH_INPUT: 1342 sm_conn->sm_engine_state = SM_SC_W2_CALCULATE_G2; 1343 break; 1344 case PK_INIT_INPUT: 1345 case PK_RESP_INPUT: 1346 case OK_BOTH_INPUT: 1347 if (setup->sm_passkey_bit < 20) { 1348 sm_sc_start_calculating_local_confirm(sm_conn); 1349 } else { 1350 sm_sc_prepare_dhkey_check(sm_conn); 1351 } 1352 break; 1353 case OOB: 1354 // TODO: implement SC OOB 1355 break; 1356 } 1357 } 1358 } 1359 1360 static uint8_t sm_sc_cmac_get_byte(uint16_t offset){ 1361 return sm_cmac_sc_buffer[offset]; 1362 } 1363 1364 static void sm_sc_cmac_done(uint8_t * hash){ 1365 log_info("sm_sc_cmac_done: "); 1366 log_info_hexdump(hash, 16); 1367 1368 sm_connection_t * sm_conn = sm_cmac_connection; 1369 sm_cmac_connection = NULL; 1370 1371 switch (sm_conn->sm_engine_state){ 1372 case SM_SC_W4_CMAC_FOR_CONFIRMATION: 1373 memcpy(setup->sm_local_confirm, hash, 16); 1374 sm_conn->sm_engine_state = SM_SC_SEND_CONFIRMATION; 1375 break; 1376 case SM_SC_W4_CMAC_FOR_CHECK_CONFIRMATION: 1377 // check 1378 if (0 != memcmp(hash, setup->sm_peer_confirm, 16)){ 1379 sm_pairing_error(sm_conn, SM_REASON_CONFIRM_VALUE_FAILED); 1380 break; 1381 } 1382 sm_sc_state_after_receiving_random(sm_conn); 1383 break; 1384 case SM_SC_W4_CALCULATE_G2: { 1385 uint32_t vab = big_endian_read_32(hash, 12) % 1000000; 1386 big_endian_store_32(setup->sm_tk, 12, vab); 1387 sm_conn->sm_engine_state = SM_SC_W4_USER_RESPONSE; 1388 sm_trigger_user_response(sm_conn); 1389 break; 1390 } 1391 case SM_SC_W4_CALCULATE_F5_SALT: 1392 memcpy(setup->sm_t, hash, 16); 1393 sm_conn->sm_engine_state = SM_SC_W2_CALCULATE_F5_MACKEY; 1394 break; 1395 case SM_SC_W4_CALCULATE_F5_MACKEY: 1396 memcpy(setup->sm_mackey, hash, 16); 1397 sm_conn->sm_engine_state = SM_SC_W2_CALCULATE_F5_LTK; 1398 break; 1399 case SM_SC_W4_CALCULATE_F5_LTK: 1400 memcpy(setup->sm_ltk, hash, 16); 1401 sm_conn->sm_engine_state = SM_SC_W2_CALCULATE_F6_FOR_DHKEY_CHECK; 1402 break; 1403 case SM_SC_W4_CALCULATE_F6_FOR_DHKEY_CHECK: 1404 memcpy(setup->sm_local_dhkey_check, hash, 16); 1405 if (sm_conn->sm_role){ 1406 // responder 1407 if (setup->sm_state_vars & SM_STATE_VAR_DHKEY_COMMAND_RECEIVED){ 1408 sm_conn->sm_engine_state = SM_SC_W2_CALCULATE_F6_TO_VERIFY_DHKEY_CHECK; 1409 } else { 1410 sm_conn->sm_engine_state = SM_SC_W4_DHKEY_CHECK_COMMAND; 1411 } 1412 } else { 1413 sm_conn->sm_engine_state = SM_SC_SEND_DHKEY_CHECK_COMMAND; 1414 } 1415 break; 1416 case SM_SC_W4_CALCULATE_F6_TO_VERIFY_DHKEY_CHECK: 1417 if (0 != memcmp(hash, setup->sm_peer_dhkey_check, 16) ){ 1418 sm_pairing_error(sm_conn, SM_REASON_DHKEY_CHECK_FAILED); 1419 break; 1420 } 1421 if (sm_conn->sm_role){ 1422 // responder 1423 sm_conn->sm_engine_state = SM_SC_SEND_DHKEY_CHECK_COMMAND; 1424 } else { 1425 // initiator 1426 sm_conn->sm_engine_state = SM_INITIATOR_PH3_SEND_START_ENCRYPTION; 1427 } 1428 break; 1429 default: 1430 log_error("sm_sc_cmac_done in state %u", sm_conn->sm_engine_state); 1431 break; 1432 } 1433 sm_run(); 1434 } 1435 1436 static void f4_engine(sm_connection_t * sm_conn, const sm_key256_t u, const sm_key256_t v, const sm_key_t x, uint8_t z){ 1437 const uint16_t message_len = 65; 1438 sm_cmac_connection = sm_conn; 1439 memcpy(sm_cmac_sc_buffer, u, 32); 1440 memcpy(sm_cmac_sc_buffer+32, v, 32); 1441 sm_cmac_sc_buffer[64] = z; 1442 log_info("f4 key"); 1443 log_info_hexdump(x, 16); 1444 log_info("f4 message"); 1445 log_info_hexdump(sm_cmac_sc_buffer, message_len); 1446 sm_cmac_general_start(x, message_len, &sm_sc_cmac_get_byte, &sm_sc_cmac_done); 1447 } 1448 1449 static const sm_key_t f5_salt = { 0x6C ,0x88, 0x83, 0x91, 0xAA, 0xF5, 0xA5, 0x38, 0x60, 0x37, 0x0B, 0xDB, 0x5A, 0x60, 0x83, 0xBE}; 1450 static const uint8_t f5_key_id[] = { 0x62, 0x74, 0x6c, 0x65 }; 1451 static const uint8_t f5_length[] = { 0x01, 0x00}; 1452 1453 static void sm_sc_calculate_dhkey(sm_key256_t dhkey){ 1454 #ifdef USE_MBEDTLS_FOR_ECDH 1455 // da * Pb 1456 mbedtls_ecp_group grp; 1457 mbedtls_ecp_group_init( &grp ); 1458 mbedtls_ecp_group_load(&grp, MBEDTLS_ECP_DP_SECP256R1); 1459 mbedtls_ecp_point Q; 1460 mbedtls_ecp_point_init( &Q ); 1461 mbedtls_mpi_read_binary(&Q.X, setup->sm_peer_qx, 32); 1462 mbedtls_mpi_read_binary(&Q.Y, setup->sm_peer_qy, 32); 1463 mbedtls_mpi_read_string(&Q.Z, 16, "1" ); 1464 mbedtls_ecp_point DH; 1465 mbedtls_ecp_point_init( &DH ); 1466 mbedtls_ecp_mul(&grp, &DH, &le_keypair.d, &Q, NULL, NULL); 1467 mbedtls_mpi_write_binary(&DH.X, dhkey, 32); 1468 #endif 1469 log_info("dhkey"); 1470 log_info_hexdump(dhkey, 32); 1471 } 1472 1473 static void f5_calculate_salt(sm_connection_t * sm_conn){ 1474 // calculate DHKEY 1475 sm_key256_t dhkey; 1476 sm_sc_calculate_dhkey(dhkey); 1477 1478 // calculate salt for f5 1479 const uint16_t message_len = 32; 1480 sm_cmac_connection = sm_conn; 1481 memcpy(sm_cmac_sc_buffer, dhkey, message_len); 1482 sm_cmac_general_start(f5_salt, message_len, &sm_sc_cmac_get_byte, &sm_sc_cmac_done); 1483 } 1484 1485 static inline void f5_mackkey(sm_connection_t * sm_conn, sm_key_t t, const sm_key_t n1, const sm_key_t n2, const sm_key56_t a1, const sm_key56_t a2){ 1486 const uint16_t message_len = 53; 1487 sm_cmac_connection = sm_conn; 1488 1489 // f5(W, N1, N2, A1, A2) = AES-CMACT (Counter = 0 || keyID || N1 || N2|| A1|| A2 || Length = 256) -- this is the MacKey 1490 sm_cmac_sc_buffer[0] = 0; 1491 memcpy(sm_cmac_sc_buffer+01, f5_key_id, 4); 1492 memcpy(sm_cmac_sc_buffer+05, n1, 16); 1493 memcpy(sm_cmac_sc_buffer+21, n2, 16); 1494 memcpy(sm_cmac_sc_buffer+37, a1, 7); 1495 memcpy(sm_cmac_sc_buffer+44, a2, 7); 1496 memcpy(sm_cmac_sc_buffer+51, f5_length, 2); 1497 log_info("f5 key"); 1498 log_info_hexdump(t, 16); 1499 log_info("f5 message for MacKey"); 1500 log_info_hexdump(sm_cmac_sc_buffer, message_len); 1501 sm_cmac_general_start(t, message_len, &sm_sc_cmac_get_byte, &sm_sc_cmac_done); 1502 } 1503 1504 static void f5_calculate_mackey(sm_connection_t * sm_conn){ 1505 sm_key56_t bd_addr_master, bd_addr_slave; 1506 bd_addr_master[0] = setup->sm_m_addr_type; 1507 bd_addr_slave[0] = setup->sm_s_addr_type; 1508 memcpy(&bd_addr_master[1], setup->sm_m_address, 6); 1509 memcpy(&bd_addr_slave[1], setup->sm_s_address, 6); 1510 if (sm_conn->sm_role){ 1511 // responder 1512 f5_mackkey(sm_conn, setup->sm_t, setup->sm_peer_nonce, setup->sm_local_nonce, bd_addr_master, bd_addr_slave); 1513 } else { 1514 // initiator 1515 f5_mackkey(sm_conn, setup->sm_t, setup->sm_local_nonce, setup->sm_peer_nonce, bd_addr_master, bd_addr_slave); 1516 } 1517 } 1518 1519 // note: must be called right after f5_mackey, as sm_cmac_buffer[1..52] will be reused 1520 static inline void f5_ltk(sm_connection_t * sm_conn, sm_key_t t){ 1521 const uint16_t message_len = 53; 1522 sm_cmac_connection = sm_conn; 1523 sm_cmac_sc_buffer[0] = 1; 1524 // 1..52 setup before 1525 log_info("f5 key"); 1526 log_info_hexdump(t, 16); 1527 log_info("f5 message for LTK"); 1528 log_info_hexdump(sm_cmac_sc_buffer, message_len); 1529 sm_cmac_general_start(t, message_len, &sm_sc_cmac_get_byte, &sm_sc_cmac_done); 1530 } 1531 1532 static void f5_calculate_ltk(sm_connection_t * sm_conn){ 1533 f5_ltk(sm_conn, setup->sm_t); 1534 } 1535 1536 static void f6_engine(sm_connection_t * sm_conn, const sm_key_t w, const sm_key_t n1, const sm_key_t n2, const sm_key_t r, const sm_key24_t io_cap, const sm_key56_t a1, const sm_key56_t a2){ 1537 const uint16_t message_len = 65; 1538 sm_cmac_connection = sm_conn; 1539 memcpy(sm_cmac_sc_buffer, n1, 16); 1540 memcpy(sm_cmac_sc_buffer+16, n2, 16); 1541 memcpy(sm_cmac_sc_buffer+32, r, 16); 1542 memcpy(sm_cmac_sc_buffer+48, io_cap, 3); 1543 memcpy(sm_cmac_sc_buffer+51, a1, 7); 1544 memcpy(sm_cmac_sc_buffer+58, a2, 7); 1545 log_info("f6 key"); 1546 log_info_hexdump(w, 16); 1547 log_info("f6 message"); 1548 log_info_hexdump(sm_cmac_sc_buffer, message_len); 1549 sm_cmac_general_start(w, 65, &sm_sc_cmac_get_byte, &sm_sc_cmac_done); 1550 } 1551 1552 // g2(U, V, X, Y) = AES-CMACX(U || V || Y) mod 2^32 1553 // - U is 256 bits 1554 // - V is 256 bits 1555 // - X is 128 bits 1556 // - Y is 128 bits 1557 static void g2_engine(sm_connection_t * sm_conn, const sm_key256_t u, const sm_key256_t v, const sm_key_t x, const sm_key_t y){ 1558 const uint16_t message_len = 80; 1559 sm_cmac_connection = sm_conn; 1560 memcpy(sm_cmac_sc_buffer, u, 32); 1561 memcpy(sm_cmac_sc_buffer+32, v, 32); 1562 memcpy(sm_cmac_sc_buffer+64, y, 16); 1563 log_info("g2 key"); 1564 log_info_hexdump(x, 16); 1565 log_info("g2 message"); 1566 log_info_hexdump(sm_cmac_sc_buffer, sizeof(sm_cmac_sc_buffer)); 1567 sm_cmac_general_start(x, message_len, &sm_sc_cmac_get_byte, &sm_sc_cmac_done); 1568 } 1569 1570 static void g2_calculate(sm_connection_t * sm_conn) { 1571 // calc Va if numeric comparison 1572 uint8_t value[32]; 1573 mbedtls_mpi_write_binary(&le_keypair.Q.X, value, sizeof(value)); 1574 if (sm_conn->sm_role){ 1575 // responder 1576 g2_engine(sm_conn, setup->sm_peer_qx, value, setup->sm_peer_nonce, setup->sm_local_nonce);; 1577 } else { 1578 // initiator 1579 g2_engine(sm_conn, value, setup->sm_peer_qx, setup->sm_local_nonce, setup->sm_peer_nonce); 1580 } 1581 } 1582 1583 static void sm_sc_calculate_local_confirm(sm_connection_t * sm_conn){ 1584 uint8_t z = 0; 1585 if (setup->sm_stk_generation_method != JUST_WORKS && setup->sm_stk_generation_method != NK_BOTH_INPUT){ 1586 // some form of passkey 1587 uint32_t pk = big_endian_read_32(setup->sm_tk, 12); 1588 z = 0x80 | ((pk >> setup->sm_passkey_bit) & 1); 1589 setup->sm_passkey_bit++; 1590 } 1591 #ifdef USE_MBEDTLS_FOR_ECDH 1592 uint8_t local_qx[32]; 1593 mbedtls_mpi_write_binary(&le_keypair.Q.X, local_qx, sizeof(local_qx)); 1594 #endif 1595 f4_engine(sm_conn, local_qx, setup->sm_peer_qx, setup->sm_local_nonce, z); 1596 } 1597 1598 static void sm_sc_calculate_remote_confirm(sm_connection_t * sm_conn){ 1599 uint8_t z = 0; 1600 if (setup->sm_stk_generation_method != JUST_WORKS && setup->sm_stk_generation_method != NK_BOTH_INPUT){ 1601 // some form of passkey 1602 uint32_t pk = big_endian_read_32(setup->sm_tk, 12); 1603 // sm_passkey_bit was increased before sending confirm value 1604 z = 0x80 | ((pk >> (setup->sm_passkey_bit-1)) & 1); 1605 } 1606 #ifdef USE_MBEDTLS_FOR_ECDH 1607 uint8_t local_qx[32]; 1608 mbedtls_mpi_write_binary(&le_keypair.Q.X, local_qx, sizeof(local_qx)); 1609 #endif 1610 f4_engine(sm_conn, setup->sm_peer_qx, local_qx, setup->sm_peer_nonce, z); 1611 } 1612 1613 static void sm_sc_prepare_dhkey_check(sm_connection_t * sm_conn){ 1614 sm_conn->sm_engine_state = SM_SC_W2_CALCULATE_F5_SALT; 1615 } 1616 1617 static void sm_sc_calculate_f6_for_dhkey_check(sm_connection_t * sm_conn){ 1618 // calculate DHKCheck 1619 sm_key56_t bd_addr_master, bd_addr_slave; 1620 bd_addr_master[0] = setup->sm_m_addr_type; 1621 bd_addr_slave[0] = setup->sm_s_addr_type; 1622 memcpy(&bd_addr_master[1], setup->sm_m_address, 6); 1623 memcpy(&bd_addr_slave[1], setup->sm_s_address, 6); 1624 uint8_t iocap_a[3]; 1625 iocap_a[0] = sm_pairing_packet_get_auth_req(setup->sm_m_preq); 1626 iocap_a[1] = sm_pairing_packet_get_oob_data_flag(setup->sm_m_preq); 1627 iocap_a[2] = sm_pairing_packet_get_io_capability(setup->sm_m_preq); 1628 uint8_t iocap_b[3]; 1629 iocap_b[0] = sm_pairing_packet_get_auth_req(setup->sm_s_pres); 1630 iocap_b[1] = sm_pairing_packet_get_oob_data_flag(setup->sm_s_pres); 1631 iocap_b[2] = sm_pairing_packet_get_io_capability(setup->sm_s_pres); 1632 if (sm_conn->sm_role){ 1633 // responder 1634 f6_engine(sm_conn, setup->sm_mackey, setup->sm_local_nonce, setup->sm_peer_nonce, setup->sm_ra, iocap_b, bd_addr_slave, bd_addr_master); 1635 } else { 1636 // initiator 1637 f6_engine(sm_conn, setup->sm_mackey, setup->sm_local_nonce, setup->sm_peer_nonce, setup->sm_rb, iocap_a, bd_addr_master, bd_addr_slave); 1638 } 1639 } 1640 1641 static void sm_sc_calculate_f6_to_verify_dhkey_check(sm_connection_t * sm_conn){ 1642 // validate E = f6() 1643 sm_key56_t bd_addr_master, bd_addr_slave; 1644 bd_addr_master[0] = setup->sm_m_addr_type; 1645 bd_addr_slave[0] = setup->sm_s_addr_type; 1646 memcpy(&bd_addr_master[1], setup->sm_m_address, 6); 1647 memcpy(&bd_addr_slave[1], setup->sm_s_address, 6); 1648 1649 uint8_t iocap_a[3]; 1650 iocap_a[0] = sm_pairing_packet_get_auth_req(setup->sm_m_preq); 1651 iocap_a[1] = sm_pairing_packet_get_oob_data_flag(setup->sm_m_preq); 1652 iocap_a[2] = sm_pairing_packet_get_io_capability(setup->sm_m_preq); 1653 uint8_t iocap_b[3]; 1654 iocap_b[0] = sm_pairing_packet_get_auth_req(setup->sm_s_pres); 1655 iocap_b[1] = sm_pairing_packet_get_oob_data_flag(setup->sm_s_pres); 1656 iocap_b[2] = sm_pairing_packet_get_io_capability(setup->sm_s_pres); 1657 if (sm_conn->sm_role){ 1658 // responder 1659 f6_engine(sm_conn, setup->sm_mackey, setup->sm_peer_nonce, setup->sm_local_nonce, setup->sm_rb, iocap_a, bd_addr_master, bd_addr_slave); 1660 } else { 1661 // initiator 1662 f6_engine(sm_conn, setup->sm_mackey, setup->sm_peer_nonce, setup->sm_local_nonce, setup->sm_ra, iocap_b, bd_addr_slave, bd_addr_master); 1663 } 1664 } 1665 #endif 1666 1667 static void sm_load_security_info(sm_connection_t * sm_connection){ 1668 int encryption_key_size; 1669 int authenticated; 1670 int authorized; 1671 1672 // fetch data from device db - incl. authenticated/authorized/key size. Note all sm_connection_X require encryption enabled 1673 le_device_db_encryption_get(sm_connection->sm_le_db_index, &setup->sm_peer_ediv, setup->sm_peer_rand, setup->sm_peer_ltk, 1674 &encryption_key_size, &authenticated, &authorized); 1675 log_info("db index %u, key size %u, authenticated %u, authorized %u", sm_connection->sm_le_db_index, encryption_key_size, authenticated, authorized); 1676 sm_connection->sm_actual_encryption_key_size = encryption_key_size; 1677 sm_connection->sm_connection_authenticated = authenticated; 1678 sm_connection->sm_connection_authorization_state = authorized ? AUTHORIZATION_GRANTED : AUTHORIZATION_UNKNOWN; 1679 } 1680 1681 static void sm_run(void){ 1682 1683 btstack_linked_list_iterator_t it; 1684 1685 // assert that we can send at least commands 1686 if (!hci_can_send_command_packet_now()) return; 1687 1688 // 1689 // non-connection related behaviour 1690 // 1691 1692 // distributed key generation 1693 switch (dkg_state){ 1694 case DKG_CALC_IRK: 1695 // already busy? 1696 if (sm_aes128_state == SM_AES128_IDLE) { 1697 // IRK = d1(IR, 1, 0) 1698 sm_key_t d1_prime; 1699 sm_d1_d_prime(1, 0, d1_prime); // plaintext 1700 dkg_next_state(); 1701 sm_aes128_start(sm_persistent_ir, d1_prime, NULL); 1702 return; 1703 } 1704 break; 1705 case DKG_CALC_DHK: 1706 // already busy? 1707 if (sm_aes128_state == SM_AES128_IDLE) { 1708 // DHK = d1(IR, 3, 0) 1709 sm_key_t d1_prime; 1710 sm_d1_d_prime(3, 0, d1_prime); // plaintext 1711 dkg_next_state(); 1712 sm_aes128_start(sm_persistent_ir, d1_prime, NULL); 1713 return; 1714 } 1715 break; 1716 default: 1717 break; 1718 } 1719 1720 #ifdef USE_MBEDTLS_FOR_ECDH 1721 if (ec_key_generation_state == EC_KEY_GENERATION_ACTIVE){ 1722 sm_random_start(NULL); 1723 return; 1724 } 1725 #endif 1726 1727 // random address updates 1728 switch (rau_state){ 1729 case RAU_GET_RANDOM: 1730 rau_next_state(); 1731 sm_random_start(NULL); 1732 return; 1733 case RAU_GET_ENC: 1734 // already busy? 1735 if (sm_aes128_state == SM_AES128_IDLE) { 1736 sm_key_t r_prime; 1737 sm_ah_r_prime(sm_random_address, r_prime); 1738 rau_next_state(); 1739 sm_aes128_start(sm_persistent_irk, r_prime, NULL); 1740 return; 1741 } 1742 break; 1743 case RAU_SET_ADDRESS: 1744 log_info("New random address: %s", bd_addr_to_str(sm_random_address)); 1745 rau_state = RAU_IDLE; 1746 hci_send_cmd(&hci_le_set_random_address, sm_random_address); 1747 return; 1748 default: 1749 break; 1750 } 1751 1752 // CMAC 1753 switch (sm_cmac_state){ 1754 case CMAC_CALC_SUBKEYS: 1755 case CMAC_CALC_MI: 1756 case CMAC_CALC_MLAST: 1757 // already busy? 1758 if (sm_aes128_state == SM_AES128_ACTIVE) break; 1759 sm_cmac_handle_aes_engine_ready(); 1760 return; 1761 default: 1762 break; 1763 } 1764 1765 // CSRK Lookup 1766 // -- if csrk lookup ready, find connection that require csrk lookup 1767 if (sm_address_resolution_idle()){ 1768 hci_connections_get_iterator(&it); 1769 while(btstack_linked_list_iterator_has_next(&it)){ 1770 hci_connection_t * hci_connection = (hci_connection_t *) btstack_linked_list_iterator_next(&it); 1771 sm_connection_t * sm_connection = &hci_connection->sm_connection; 1772 if (sm_connection->sm_irk_lookup_state == IRK_LOOKUP_W4_READY){ 1773 // and start lookup 1774 sm_address_resolution_start_lookup(sm_connection->sm_peer_addr_type, sm_connection->sm_handle, sm_connection->sm_peer_address, ADDRESS_RESOLUTION_FOR_CONNECTION, sm_connection); 1775 sm_connection->sm_irk_lookup_state = IRK_LOOKUP_STARTED; 1776 break; 1777 } 1778 } 1779 } 1780 1781 // -- if csrk lookup ready, resolved addresses for received addresses 1782 if (sm_address_resolution_idle()) { 1783 if (!btstack_linked_list_empty(&sm_address_resolution_general_queue)){ 1784 sm_lookup_entry_t * entry = (sm_lookup_entry_t *) sm_address_resolution_general_queue; 1785 btstack_linked_list_remove(&sm_address_resolution_general_queue, (btstack_linked_item_t *) entry); 1786 sm_address_resolution_start_lookup(entry->address_type, 0, entry->address, ADDRESS_RESOLUTION_GENERAL, NULL); 1787 btstack_memory_sm_lookup_entry_free(entry); 1788 } 1789 } 1790 1791 // -- Continue with CSRK device lookup by public or resolvable private address 1792 if (!sm_address_resolution_idle()){ 1793 log_info("LE Device Lookup: device %u/%u", sm_address_resolution_test, le_device_db_count()); 1794 while (sm_address_resolution_test < le_device_db_count()){ 1795 int addr_type; 1796 bd_addr_t addr; 1797 sm_key_t irk; 1798 le_device_db_info(sm_address_resolution_test, &addr_type, addr, irk); 1799 log_info("device type %u, addr: %s", addr_type, bd_addr_to_str(addr)); 1800 1801 if (sm_address_resolution_addr_type == addr_type && memcmp(addr, sm_address_resolution_address, 6) == 0){ 1802 log_info("LE Device Lookup: found CSRK by { addr_type, address} "); 1803 sm_address_resolution_handle_event(ADDRESS_RESOLUTION_SUCEEDED); 1804 break; 1805 } 1806 1807 if (sm_address_resolution_addr_type == 0){ 1808 sm_address_resolution_test++; 1809 continue; 1810 } 1811 1812 if (sm_aes128_state == SM_AES128_ACTIVE) break; 1813 1814 log_info("LE Device Lookup: calculate AH"); 1815 log_info_key("IRK", irk); 1816 1817 sm_key_t r_prime; 1818 sm_ah_r_prime(sm_address_resolution_address, r_prime); 1819 sm_address_resolution_ah_calculation_active = 1; 1820 sm_aes128_start(irk, r_prime, sm_address_resolution_context); // keep context 1821 return; 1822 } 1823 1824 if (sm_address_resolution_test >= le_device_db_count()){ 1825 log_info("LE Device Lookup: not found"); 1826 sm_address_resolution_handle_event(ADDRESS_RESOLUTION_FAILED); 1827 } 1828 } 1829 1830 1831 // 1832 // active connection handling 1833 // -- use loop to handle next connection if lock on setup context is released 1834 1835 while (1) { 1836 1837 // Find connections that requires setup context and make active if no other is locked 1838 hci_connections_get_iterator(&it); 1839 while(!sm_active_connection && btstack_linked_list_iterator_has_next(&it)){ 1840 hci_connection_t * hci_connection = (hci_connection_t *) btstack_linked_list_iterator_next(&it); 1841 sm_connection_t * sm_connection = &hci_connection->sm_connection; 1842 // - if no connection locked and we're ready/waiting for setup context, fetch it and start 1843 int done = 1; 1844 int err; 1845 switch (sm_connection->sm_engine_state) { 1846 case SM_RESPONDER_SEND_SECURITY_REQUEST: 1847 // send packet if possible, 1848 if (l2cap_can_send_fixed_channel_packet_now(sm_connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL)){ 1849 const uint8_t buffer[2] = { SM_CODE_SECURITY_REQUEST, SM_AUTHREQ_BONDING}; 1850 sm_connection->sm_engine_state = SM_RESPONDER_PH1_W4_PAIRING_REQUEST; 1851 l2cap_send_connectionless(sm_connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 1852 } else { 1853 l2cap_request_can_send_fix_channel_now_event(sm_connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL); 1854 } 1855 // don't lock sxetup context yet 1856 done = 0; 1857 break; 1858 case SM_RESPONDER_PH1_PAIRING_REQUEST_RECEIVED: 1859 sm_init_setup(sm_connection); 1860 // recover pairing request 1861 memcpy(&setup->sm_m_preq, &sm_connection->sm_m_preq, sizeof(sm_pairing_packet_t)); 1862 err = sm_stk_generation_init(sm_connection); 1863 if (err){ 1864 setup->sm_pairing_failed_reason = err; 1865 sm_connection->sm_engine_state = SM_GENERAL_SEND_PAIRING_FAILED; 1866 break; 1867 } 1868 sm_timeout_start(sm_connection); 1869 // generate random number first, if we need to show passkey 1870 if (setup->sm_stk_generation_method == PK_INIT_INPUT){ 1871 sm_connection->sm_engine_state = SM_PH2_GET_RANDOM_TK; 1872 break; 1873 } 1874 sm_connection->sm_engine_state = SM_RESPONDER_PH1_SEND_PAIRING_RESPONSE; 1875 break; 1876 case SM_INITIATOR_PH0_HAS_LTK: 1877 sm_load_security_info(sm_connection); 1878 sm_connection->sm_engine_state = SM_INITIATOR_PH0_SEND_START_ENCRYPTION; 1879 break; 1880 case SM_RESPONDER_PH0_RECEIVED_LTK: 1881 switch (sm_connection->sm_irk_lookup_state){ 1882 case IRK_LOOKUP_SUCCEEDED:{ 1883 sm_load_security_info(sm_connection); 1884 sm_connection->sm_engine_state = SM_RESPONDER_PH2_SEND_LTK_REPLY; 1885 break; 1886 } 1887 case IRK_LOOKUP_FAILED: 1888 // assume that we don't have a LTK for ediv == 0 and random == null 1889 if (sm_connection->sm_local_ediv == 0 && sm_is_null_random(sm_connection->sm_local_rand)){ 1890 log_info("LTK Request: ediv & random are empty"); 1891 sm_connection->sm_engine_state = SM_RESPONDER_PH0_SEND_LTK_REQUESTED_NEGATIVE_REPLY; 1892 // TODO: no need to lock context yet -> done = 0; 1893 break; 1894 } 1895 // re-establish previously used LTK using Rand and EDIV 1896 memcpy(setup->sm_local_rand, sm_connection->sm_local_rand, 8); 1897 setup->sm_local_ediv = sm_connection->sm_local_ediv; 1898 // re-establish used key encryption size 1899 // no db for encryption size hack: encryption size is stored in lowest nibble of setup->sm_local_rand 1900 sm_connection->sm_actual_encryption_key_size = (setup->sm_local_rand[7] & 0x0f) + 1; 1901 // no db for authenticated flag hack: flag is stored in bit 4 of LSB 1902 sm_connection->sm_connection_authenticated = (setup->sm_local_rand[7] & 0x10) >> 4; 1903 log_info("sm: received ltk request with key size %u, authenticated %u", 1904 sm_connection->sm_actual_encryption_key_size, sm_connection->sm_connection_authenticated); 1905 sm_connection->sm_engine_state = SM_RESPONDER_PH4_Y_GET_ENC; 1906 break; 1907 default: 1908 // just wait until IRK lookup is completed 1909 // don't lock sxetup context yet 1910 done = 0; 1911 break; 1912 } 1913 break; 1914 case SM_INITIATOR_PH1_W2_SEND_PAIRING_REQUEST: 1915 sm_init_setup(sm_connection); 1916 sm_timeout_start(sm_connection); 1917 sm_connection->sm_engine_state = SM_INITIATOR_PH1_SEND_PAIRING_REQUEST; 1918 break; 1919 default: 1920 done = 0; 1921 break; 1922 } 1923 if (done){ 1924 sm_active_connection = sm_connection->sm_handle; 1925 log_info("sm: connection 0x%04x locked setup context as %s", sm_active_connection, sm_connection->sm_role ? "responder" : "initiator"); 1926 } 1927 } 1928 1929 // 1930 // active connection handling 1931 // 1932 1933 if (sm_active_connection == 0) return; 1934 1935 // assert that we could send a SM PDU - not needed for all of the following 1936 if (!l2cap_can_send_fixed_channel_packet_now(sm_active_connection, L2CAP_CID_SECURITY_MANAGER_PROTOCOL)) { 1937 l2cap_request_can_send_fix_channel_now_event(sm_active_connection, L2CAP_CID_SECURITY_MANAGER_PROTOCOL); 1938 return; 1939 } 1940 1941 sm_connection_t * connection = sm_get_connection_for_handle(sm_active_connection); 1942 if (!connection) return; 1943 1944 sm_key_t plaintext; 1945 int key_distribution_flags; 1946 1947 log_info("sm_run: state %u", connection->sm_engine_state); 1948 1949 // responding state 1950 switch (connection->sm_engine_state){ 1951 1952 // general 1953 case SM_GENERAL_SEND_PAIRING_FAILED: { 1954 uint8_t buffer[2]; 1955 buffer[0] = SM_CODE_PAIRING_FAILED; 1956 buffer[1] = setup->sm_pairing_failed_reason; 1957 connection->sm_engine_state = connection->sm_role ? SM_RESPONDER_IDLE : SM_INITIATOR_CONNECTED; 1958 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 1959 sm_done_for_handle(connection->sm_handle); 1960 break; 1961 } 1962 1963 #ifdef ENABLE_LE_SECURE_CONNECTIONS 1964 case SM_SC_W2_GET_RANDOM_A: 1965 sm_random_start(connection); 1966 connection->sm_engine_state = SM_SC_W4_GET_RANDOM_A; 1967 break; 1968 case SM_SC_W2_GET_RANDOM_B: 1969 sm_random_start(connection); 1970 connection->sm_engine_state = SM_SC_W4_GET_RANDOM_B; 1971 break; 1972 case SM_SC_W2_CMAC_FOR_CONFIRMATION: 1973 if (!sm_cmac_ready()) break; 1974 connection->sm_engine_state = SM_SC_W4_CMAC_FOR_CONFIRMATION; 1975 sm_sc_calculate_local_confirm(connection); 1976 break; 1977 case SM_SC_W2_CMAC_FOR_CHECK_CONFIRMATION: 1978 if (!sm_cmac_ready()) break; 1979 connection->sm_engine_state = SM_SC_W4_CMAC_FOR_CHECK_CONFIRMATION; 1980 sm_sc_calculate_remote_confirm(connection); 1981 break; 1982 case SM_SC_W2_CALCULATE_F6_FOR_DHKEY_CHECK: 1983 if (!sm_cmac_ready()) break; 1984 connection->sm_engine_state = SM_SC_W4_CALCULATE_F6_FOR_DHKEY_CHECK; 1985 sm_sc_calculate_f6_for_dhkey_check(connection); 1986 break; 1987 case SM_SC_W2_CALCULATE_F6_TO_VERIFY_DHKEY_CHECK: 1988 if (!sm_cmac_ready()) break; 1989 connection->sm_engine_state = SM_SC_W4_CALCULATE_F6_TO_VERIFY_DHKEY_CHECK; 1990 sm_sc_calculate_f6_to_verify_dhkey_check(connection); 1991 break; 1992 case SM_SC_W2_CALCULATE_F5_SALT: 1993 if (!sm_cmac_ready()) break; 1994 connection->sm_engine_state = SM_SC_W4_CALCULATE_F5_SALT; 1995 f5_calculate_salt(connection); 1996 break; 1997 case SM_SC_W2_CALCULATE_F5_MACKEY: 1998 if (!sm_cmac_ready()) break; 1999 connection->sm_engine_state = SM_SC_W4_CALCULATE_F5_MACKEY; 2000 f5_calculate_mackey(connection); 2001 break; 2002 case SM_SC_W2_CALCULATE_F5_LTK: 2003 if (!sm_cmac_ready()) break; 2004 connection->sm_engine_state = SM_SC_W4_CALCULATE_F5_LTK; 2005 f5_calculate_ltk(connection); 2006 break; 2007 case SM_SC_W2_CALCULATE_G2: 2008 if (!sm_cmac_ready()) break; 2009 connection->sm_engine_state = SM_SC_W4_CALCULATE_G2; 2010 g2_calculate(connection); 2011 break; 2012 2013 #endif 2014 // initiator side 2015 case SM_INITIATOR_PH0_SEND_START_ENCRYPTION: { 2016 sm_key_t peer_ltk_flipped; 2017 reverse_128(setup->sm_peer_ltk, peer_ltk_flipped); 2018 connection->sm_engine_state = SM_INITIATOR_PH0_W4_CONNECTION_ENCRYPTED; 2019 log_info("sm: hci_le_start_encryption ediv 0x%04x", setup->sm_peer_ediv); 2020 uint32_t rand_high = big_endian_read_32(setup->sm_peer_rand, 0); 2021 uint32_t rand_low = big_endian_read_32(setup->sm_peer_rand, 4); 2022 hci_send_cmd(&hci_le_start_encryption, connection->sm_handle,rand_low, rand_high, setup->sm_peer_ediv, peer_ltk_flipped); 2023 return; 2024 } 2025 2026 case SM_INITIATOR_PH1_SEND_PAIRING_REQUEST: 2027 sm_pairing_packet_set_code(setup->sm_m_preq, SM_CODE_PAIRING_REQUEST); 2028 connection->sm_engine_state = SM_INITIATOR_PH1_W4_PAIRING_RESPONSE; 2029 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) &setup->sm_m_preq, sizeof(sm_pairing_packet_t)); 2030 sm_timeout_reset(connection); 2031 break; 2032 2033 // responder side 2034 case SM_RESPONDER_PH0_SEND_LTK_REQUESTED_NEGATIVE_REPLY: 2035 connection->sm_engine_state = SM_RESPONDER_IDLE; 2036 hci_send_cmd(&hci_le_long_term_key_negative_reply, connection->sm_handle); 2037 return; 2038 2039 #ifdef ENABLE_LE_SECURE_CONNECTIONS 2040 case SM_SC_SEND_PUBLIC_KEY_COMMAND: { 2041 uint8_t buffer[65]; 2042 buffer[0] = SM_CODE_PAIRING_PUBLIC_KEY; 2043 // 2044 #ifdef USE_MBEDTLS_FOR_ECDH 2045 uint8_t value[32]; 2046 mbedtls_mpi_write_binary(&le_keypair.Q.X, value, sizeof(value)); 2047 reverse_256(value, &buffer[1]); 2048 mbedtls_mpi_write_binary(&le_keypair.Q.Y, value, sizeof(value)); 2049 reverse_256(value, &buffer[33]); 2050 #endif 2051 2052 // stk generation method 2053 // passkey entry: notify app to show passkey or to request passkey 2054 switch (setup->sm_stk_generation_method){ 2055 case JUST_WORKS: 2056 case NK_BOTH_INPUT: 2057 if (connection->sm_role){ 2058 // responder 2059 sm_sc_start_calculating_local_confirm(connection); 2060 } else { 2061 // initiator 2062 connection->sm_engine_state = SM_SC_W4_PUBLIC_KEY_COMMAND; 2063 } 2064 break; 2065 case PK_INIT_INPUT: 2066 case PK_RESP_INPUT: 2067 case OK_BOTH_INPUT: 2068 // use random TK for display 2069 memcpy(setup->sm_ra, setup->sm_tk, 16); 2070 memcpy(setup->sm_rb, setup->sm_tk, 16); 2071 setup->sm_passkey_bit = 0; 2072 2073 if (connection->sm_role){ 2074 // responder 2075 connection->sm_engine_state = SM_SC_W4_CONFIRMATION; 2076 } else { 2077 // initiator 2078 connection->sm_engine_state = SM_SC_W4_PUBLIC_KEY_COMMAND; 2079 } 2080 sm_trigger_user_response(connection); 2081 break; 2082 case OOB: 2083 // TODO: implement SC OOB 2084 break; 2085 } 2086 2087 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2088 sm_timeout_reset(connection); 2089 break; 2090 } 2091 case SM_SC_SEND_CONFIRMATION: { 2092 uint8_t buffer[17]; 2093 buffer[0] = SM_CODE_PAIRING_CONFIRM; 2094 reverse_128(setup->sm_local_confirm, &buffer[1]); 2095 if (connection->sm_role){ 2096 connection->sm_engine_state = SM_SC_W4_PAIRING_RANDOM; 2097 } else { 2098 connection->sm_engine_state = SM_SC_W4_CONFIRMATION; 2099 } 2100 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2101 sm_timeout_reset(connection); 2102 break; 2103 } 2104 case SM_SC_SEND_PAIRING_RANDOM: { 2105 uint8_t buffer[17]; 2106 buffer[0] = SM_CODE_PAIRING_RANDOM; 2107 reverse_128(setup->sm_local_nonce, &buffer[1]); 2108 if (setup->sm_stk_generation_method != JUST_WORKS && setup->sm_stk_generation_method != NK_BOTH_INPUT && setup->sm_passkey_bit < 20){ 2109 if (connection->sm_role){ 2110 // responder 2111 connection->sm_engine_state = SM_SC_W4_CONFIRMATION; 2112 } else { 2113 // initiator 2114 connection->sm_engine_state = SM_SC_W4_PAIRING_RANDOM; 2115 } 2116 } else { 2117 if (connection->sm_role){ 2118 // responder 2119 if (setup->sm_stk_generation_method == NK_BOTH_INPUT){ 2120 connection->sm_engine_state = SM_SC_W2_CALCULATE_G2; 2121 } else { 2122 sm_sc_prepare_dhkey_check(connection); 2123 } 2124 } else { 2125 // initiator 2126 connection->sm_engine_state = SM_SC_W4_PAIRING_RANDOM; 2127 } 2128 } 2129 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2130 sm_timeout_reset(connection); 2131 break; 2132 } 2133 case SM_SC_SEND_DHKEY_CHECK_COMMAND: { 2134 uint8_t buffer[17]; 2135 buffer[0] = SM_CODE_PAIRING_DHKEY_CHECK; 2136 reverse_128(setup->sm_local_dhkey_check, &buffer[1]); 2137 2138 if (connection->sm_role){ 2139 connection->sm_engine_state = SM_SC_W4_LTK_REQUEST_SC; 2140 } else { 2141 connection->sm_engine_state = SM_SC_W4_DHKEY_CHECK_COMMAND; 2142 } 2143 2144 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2145 sm_timeout_reset(connection); 2146 break; 2147 } 2148 2149 #endif 2150 case SM_RESPONDER_PH1_SEND_PAIRING_RESPONSE: 2151 // echo initiator for now 2152 sm_pairing_packet_set_code(setup->sm_s_pres,SM_CODE_PAIRING_RESPONSE); 2153 key_distribution_flags = sm_key_distribution_flags_for_auth_req(); 2154 2155 connection->sm_engine_state = SM_RESPONDER_PH1_W4_PAIRING_CONFIRM; 2156 #ifdef ENABLE_LE_SECURE_CONNECTIONS 2157 if (setup->sm_use_secure_connections){ 2158 connection->sm_engine_state = SM_SC_W4_PUBLIC_KEY_COMMAND; 2159 // skip LTK/EDIV for SC 2160 key_distribution_flags &= ~SM_KEYDIST_ENC_KEY; 2161 } 2162 #endif 2163 sm_pairing_packet_set_initiator_key_distribution(setup->sm_s_pres, sm_pairing_packet_get_initiator_key_distribution(setup->sm_m_preq) & key_distribution_flags); 2164 sm_pairing_packet_set_responder_key_distribution(setup->sm_s_pres, sm_pairing_packet_get_responder_key_distribution(setup->sm_m_preq) & key_distribution_flags); 2165 2166 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) &setup->sm_s_pres, sizeof(sm_pairing_packet_t)); 2167 sm_timeout_reset(connection); 2168 // SC Numeric Comparison will trigger user response after public keys & nonces have been exchanged 2169 if (setup->sm_stk_generation_method == JUST_WORKS){ 2170 sm_trigger_user_response(connection); 2171 } 2172 return; 2173 2174 case SM_PH2_SEND_PAIRING_RANDOM: { 2175 uint8_t buffer[17]; 2176 buffer[0] = SM_CODE_PAIRING_RANDOM; 2177 reverse_128(setup->sm_local_random, &buffer[1]); 2178 if (connection->sm_role){ 2179 connection->sm_engine_state = SM_RESPONDER_PH2_W4_LTK_REQUEST; 2180 } else { 2181 connection->sm_engine_state = SM_INITIATOR_PH2_W4_PAIRING_RANDOM; 2182 } 2183 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2184 sm_timeout_reset(connection); 2185 break; 2186 } 2187 2188 case SM_PH2_GET_RANDOM_TK: 2189 case SM_PH2_C1_GET_RANDOM_A: 2190 case SM_PH2_C1_GET_RANDOM_B: 2191 case SM_PH3_GET_RANDOM: 2192 case SM_PH3_GET_DIV: 2193 sm_next_responding_state(connection); 2194 sm_random_start(connection); 2195 return; 2196 2197 case SM_PH2_C1_GET_ENC_B: 2198 case SM_PH2_C1_GET_ENC_D: 2199 // already busy? 2200 if (sm_aes128_state == SM_AES128_ACTIVE) break; 2201 sm_next_responding_state(connection); 2202 sm_aes128_start(setup->sm_tk, setup->sm_c1_t3_value, connection); 2203 return; 2204 2205 case SM_PH3_LTK_GET_ENC: 2206 case SM_RESPONDER_PH4_LTK_GET_ENC: 2207 // already busy? 2208 if (sm_aes128_state == SM_AES128_IDLE) { 2209 sm_key_t d_prime; 2210 sm_d1_d_prime(setup->sm_local_div, 0, d_prime); 2211 sm_next_responding_state(connection); 2212 sm_aes128_start(sm_persistent_er, d_prime, connection); 2213 return; 2214 } 2215 break; 2216 2217 case SM_PH3_CSRK_GET_ENC: 2218 // already busy? 2219 if (sm_aes128_state == SM_AES128_IDLE) { 2220 sm_key_t d_prime; 2221 sm_d1_d_prime(setup->sm_local_div, 1, d_prime); 2222 sm_next_responding_state(connection); 2223 sm_aes128_start(sm_persistent_er, d_prime, connection); 2224 return; 2225 } 2226 break; 2227 2228 case SM_PH2_C1_GET_ENC_C: 2229 // already busy? 2230 if (sm_aes128_state == SM_AES128_ACTIVE) break; 2231 // calculate m_confirm using aes128 engine - step 1 2232 sm_c1_t1(setup->sm_peer_random, (uint8_t*) &setup->sm_m_preq, (uint8_t*) &setup->sm_s_pres, setup->sm_m_addr_type, setup->sm_s_addr_type, plaintext); 2233 sm_next_responding_state(connection); 2234 sm_aes128_start(setup->sm_tk, plaintext, connection); 2235 break; 2236 case SM_PH2_C1_GET_ENC_A: 2237 // already busy? 2238 if (sm_aes128_state == SM_AES128_ACTIVE) break; 2239 // calculate confirm using aes128 engine - step 1 2240 sm_c1_t1(setup->sm_local_random, (uint8_t*) &setup->sm_m_preq, (uint8_t*) &setup->sm_s_pres, setup->sm_m_addr_type, setup->sm_s_addr_type, plaintext); 2241 sm_next_responding_state(connection); 2242 sm_aes128_start(setup->sm_tk, plaintext, connection); 2243 break; 2244 case SM_PH2_CALC_STK: 2245 // already busy? 2246 if (sm_aes128_state == SM_AES128_ACTIVE) break; 2247 // calculate STK 2248 if (connection->sm_role){ 2249 sm_s1_r_prime(setup->sm_local_random, setup->sm_peer_random, plaintext); 2250 } else { 2251 sm_s1_r_prime(setup->sm_peer_random, setup->sm_local_random, plaintext); 2252 } 2253 sm_next_responding_state(connection); 2254 sm_aes128_start(setup->sm_tk, plaintext, connection); 2255 break; 2256 case SM_PH3_Y_GET_ENC: 2257 // already busy? 2258 if (sm_aes128_state == SM_AES128_ACTIVE) break; 2259 // PH3B2 - calculate Y from - enc 2260 // Y = dm(DHK, Rand) 2261 sm_dm_r_prime(setup->sm_local_rand, plaintext); 2262 sm_next_responding_state(connection); 2263 sm_aes128_start(sm_persistent_dhk, plaintext, connection); 2264 return; 2265 case SM_PH2_C1_SEND_PAIRING_CONFIRM: { 2266 uint8_t buffer[17]; 2267 buffer[0] = SM_CODE_PAIRING_CONFIRM; 2268 reverse_128(setup->sm_local_confirm, &buffer[1]); 2269 if (connection->sm_role){ 2270 connection->sm_engine_state = SM_RESPONDER_PH2_W4_PAIRING_RANDOM; 2271 } else { 2272 connection->sm_engine_state = SM_INITIATOR_PH2_W4_PAIRING_CONFIRM; 2273 } 2274 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2275 sm_timeout_reset(connection); 2276 return; 2277 } 2278 case SM_RESPONDER_PH2_SEND_LTK_REPLY: { 2279 sm_key_t stk_flipped; 2280 reverse_128(setup->sm_ltk, stk_flipped); 2281 connection->sm_engine_state = SM_PH2_W4_CONNECTION_ENCRYPTED; 2282 hci_send_cmd(&hci_le_long_term_key_request_reply, connection->sm_handle, stk_flipped); 2283 return; 2284 } 2285 case SM_INITIATOR_PH3_SEND_START_ENCRYPTION: { 2286 sm_key_t stk_flipped; 2287 reverse_128(setup->sm_ltk, stk_flipped); 2288 connection->sm_engine_state = SM_PH2_W4_CONNECTION_ENCRYPTED; 2289 hci_send_cmd(&hci_le_start_encryption, connection->sm_handle, 0, 0, 0, stk_flipped); 2290 return; 2291 } 2292 case SM_RESPONDER_PH4_SEND_LTK: { 2293 sm_key_t ltk_flipped; 2294 reverse_128(setup->sm_ltk, ltk_flipped); 2295 connection->sm_engine_state = SM_RESPONDER_IDLE; 2296 hci_send_cmd(&hci_le_long_term_key_request_reply, connection->sm_handle, ltk_flipped); 2297 return; 2298 } 2299 case SM_RESPONDER_PH4_Y_GET_ENC: 2300 // already busy? 2301 if (sm_aes128_state == SM_AES128_ACTIVE) break; 2302 log_info("LTK Request: recalculating with ediv 0x%04x", setup->sm_local_ediv); 2303 // Y = dm(DHK, Rand) 2304 sm_dm_r_prime(setup->sm_local_rand, plaintext); 2305 sm_next_responding_state(connection); 2306 sm_aes128_start(sm_persistent_dhk, plaintext, connection); 2307 return; 2308 2309 case SM_PH3_DISTRIBUTE_KEYS: 2310 if (setup->sm_key_distribution_send_set & SM_KEYDIST_FLAG_ENCRYPTION_INFORMATION){ 2311 setup->sm_key_distribution_send_set &= ~SM_KEYDIST_FLAG_ENCRYPTION_INFORMATION; 2312 uint8_t buffer[17]; 2313 buffer[0] = SM_CODE_ENCRYPTION_INFORMATION; 2314 reverse_128(setup->sm_ltk, &buffer[1]); 2315 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2316 sm_timeout_reset(connection); 2317 return; 2318 } 2319 if (setup->sm_key_distribution_send_set & SM_KEYDIST_FLAG_MASTER_IDENTIFICATION){ 2320 setup->sm_key_distribution_send_set &= ~SM_KEYDIST_FLAG_MASTER_IDENTIFICATION; 2321 uint8_t buffer[11]; 2322 buffer[0] = SM_CODE_MASTER_IDENTIFICATION; 2323 little_endian_store_16(buffer, 1, setup->sm_local_ediv); 2324 reverse_64(setup->sm_local_rand, &buffer[3]); 2325 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2326 sm_timeout_reset(connection); 2327 return; 2328 } 2329 if (setup->sm_key_distribution_send_set & SM_KEYDIST_FLAG_IDENTITY_INFORMATION){ 2330 setup->sm_key_distribution_send_set &= ~SM_KEYDIST_FLAG_IDENTITY_INFORMATION; 2331 uint8_t buffer[17]; 2332 buffer[0] = SM_CODE_IDENTITY_INFORMATION; 2333 reverse_128(sm_persistent_irk, &buffer[1]); 2334 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2335 sm_timeout_reset(connection); 2336 return; 2337 } 2338 if (setup->sm_key_distribution_send_set & SM_KEYDIST_FLAG_IDENTITY_ADDRESS_INFORMATION){ 2339 setup->sm_key_distribution_send_set &= ~SM_KEYDIST_FLAG_IDENTITY_ADDRESS_INFORMATION; 2340 bd_addr_t local_address; 2341 uint8_t buffer[8]; 2342 buffer[0] = SM_CODE_IDENTITY_ADDRESS_INFORMATION; 2343 gap_advertisements_get_address(&buffer[1], local_address); 2344 reverse_bd_addr(local_address, &buffer[2]); 2345 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2346 sm_timeout_reset(connection); 2347 return; 2348 } 2349 if (setup->sm_key_distribution_send_set & SM_KEYDIST_FLAG_SIGNING_IDENTIFICATION){ 2350 setup->sm_key_distribution_send_set &= ~SM_KEYDIST_FLAG_SIGNING_IDENTIFICATION; 2351 2352 // hack to reproduce test runs 2353 if (test_use_fixed_local_csrk){ 2354 memset(setup->sm_local_csrk, 0xcc, 16); 2355 } 2356 2357 uint8_t buffer[17]; 2358 buffer[0] = SM_CODE_SIGNING_INFORMATION; 2359 reverse_128(setup->sm_local_csrk, &buffer[1]); 2360 l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer)); 2361 sm_timeout_reset(connection); 2362 return; 2363 } 2364 2365 // keys are sent 2366 if (connection->sm_role){ 2367 // slave -> receive master keys if any 2368 if (sm_key_distribution_all_received(connection)){ 2369 sm_key_distribution_handle_all_received(connection); 2370 connection->sm_engine_state = SM_RESPONDER_IDLE; 2371 sm_done_for_handle(connection->sm_handle); 2372 } else { 2373 connection->sm_engine_state = SM_PH3_RECEIVE_KEYS; 2374 } 2375 } else { 2376 // master -> all done 2377 connection->sm_engine_state = SM_INITIATOR_CONNECTED; 2378 sm_done_for_handle(connection->sm_handle); 2379 } 2380 break; 2381 2382 default: 2383 break; 2384 } 2385 2386 // check again if active connection was released 2387 if (sm_active_connection) break; 2388 } 2389 } 2390 2391 // note: aes engine is ready as we just got the aes result 2392 static void sm_handle_encryption_result(uint8_t * data){ 2393 2394 sm_aes128_state = SM_AES128_IDLE; 2395 2396 if (sm_address_resolution_ah_calculation_active){ 2397 sm_address_resolution_ah_calculation_active = 0; 2398 // compare calulated address against connecting device 2399 uint8_t hash[3]; 2400 reverse_24(data, hash); 2401 if (memcmp(&sm_address_resolution_address[3], hash, 3) == 0){ 2402 log_info("LE Device Lookup: matched resolvable private address"); 2403 sm_address_resolution_handle_event(ADDRESS_RESOLUTION_SUCEEDED); 2404 return; 2405 } 2406 // no match, try next 2407 sm_address_resolution_test++; 2408 return; 2409 } 2410 2411 switch (dkg_state){ 2412 case DKG_W4_IRK: 2413 reverse_128(data, sm_persistent_irk); 2414 log_info_key("irk", sm_persistent_irk); 2415 dkg_next_state(); 2416 return; 2417 case DKG_W4_DHK: 2418 reverse_128(data, sm_persistent_dhk); 2419 log_info_key("dhk", sm_persistent_dhk); 2420 dkg_next_state(); 2421 // SM Init Finished 2422 return; 2423 default: 2424 break; 2425 } 2426 2427 switch (rau_state){ 2428 case RAU_W4_ENC: 2429 reverse_24(data, &sm_random_address[3]); 2430 rau_next_state(); 2431 return; 2432 default: 2433 break; 2434 } 2435 2436 switch (sm_cmac_state){ 2437 case CMAC_W4_SUBKEYS: 2438 case CMAC_W4_MI: 2439 case CMAC_W4_MLAST: 2440 { 2441 sm_key_t t; 2442 reverse_128(data, t); 2443 sm_cmac_handle_encryption_result(t); 2444 } 2445 return; 2446 default: 2447 break; 2448 } 2449 2450 // retrieve sm_connection provided to sm_aes128_start_encryption 2451 sm_connection_t * connection = (sm_connection_t*) sm_aes128_context; 2452 if (!connection) return; 2453 switch (connection->sm_engine_state){ 2454 case SM_PH2_C1_W4_ENC_A: 2455 case SM_PH2_C1_W4_ENC_C: 2456 { 2457 sm_key_t t2; 2458 reverse_128(data, t2); 2459 sm_c1_t3(t2, setup->sm_m_address, setup->sm_s_address, setup->sm_c1_t3_value); 2460 } 2461 sm_next_responding_state(connection); 2462 return; 2463 case SM_PH2_C1_W4_ENC_B: 2464 reverse_128(data, setup->sm_local_confirm); 2465 log_info_key("c1!", setup->sm_local_confirm); 2466 connection->sm_engine_state = SM_PH2_C1_SEND_PAIRING_CONFIRM; 2467 return; 2468 case SM_PH2_C1_W4_ENC_D: 2469 { 2470 sm_key_t peer_confirm_test; 2471 reverse_128(data, peer_confirm_test); 2472 log_info_key("c1!", peer_confirm_test); 2473 if (memcmp(setup->sm_peer_confirm, peer_confirm_test, 16) != 0){ 2474 setup->sm_pairing_failed_reason = SM_REASON_CONFIRM_VALUE_FAILED; 2475 connection->sm_engine_state = SM_GENERAL_SEND_PAIRING_FAILED; 2476 return; 2477 } 2478 if (connection->sm_role){ 2479 connection->sm_engine_state = SM_PH2_SEND_PAIRING_RANDOM; 2480 } else { 2481 connection->sm_engine_state = SM_PH2_CALC_STK; 2482 } 2483 } 2484 return; 2485 case SM_PH2_W4_STK: 2486 reverse_128(data, setup->sm_ltk); 2487 sm_truncate_key(setup->sm_ltk, connection->sm_actual_encryption_key_size); 2488 log_info_key("stk", setup->sm_ltk); 2489 if (connection->sm_role){ 2490 connection->sm_engine_state = SM_RESPONDER_PH2_SEND_LTK_REPLY; 2491 } else { 2492 connection->sm_engine_state = SM_INITIATOR_PH3_SEND_START_ENCRYPTION; 2493 } 2494 return; 2495 case SM_PH3_Y_W4_ENC:{ 2496 sm_key_t y128; 2497 reverse_128(data, y128); 2498 setup->sm_local_y = big_endian_read_16(y128, 14); 2499 log_info_hex16("y", setup->sm_local_y); 2500 // PH3B3 - calculate EDIV 2501 setup->sm_local_ediv = setup->sm_local_y ^ setup->sm_local_div; 2502 log_info_hex16("ediv", setup->sm_local_ediv); 2503 // PH3B4 - calculate LTK - enc 2504 // LTK = d1(ER, DIV, 0)) 2505 connection->sm_engine_state = SM_PH3_LTK_GET_ENC; 2506 return; 2507 } 2508 case SM_RESPONDER_PH4_Y_W4_ENC:{ 2509 sm_key_t y128; 2510 reverse_128(data, y128); 2511 setup->sm_local_y = big_endian_read_16(y128, 14); 2512 log_info_hex16("y", setup->sm_local_y); 2513 2514 // PH3B3 - calculate DIV 2515 setup->sm_local_div = setup->sm_local_y ^ setup->sm_local_ediv; 2516 log_info_hex16("ediv", setup->sm_local_ediv); 2517 // PH3B4 - calculate LTK - enc 2518 // LTK = d1(ER, DIV, 0)) 2519 connection->sm_engine_state = SM_RESPONDER_PH4_LTK_GET_ENC; 2520 return; 2521 } 2522 case SM_PH3_LTK_W4_ENC: 2523 reverse_128(data, setup->sm_ltk); 2524 log_info_key("ltk", setup->sm_ltk); 2525 // calc CSRK next 2526 connection->sm_engine_state = SM_PH3_CSRK_GET_ENC; 2527 return; 2528 case SM_PH3_CSRK_W4_ENC: 2529 reverse_128(data, setup->sm_local_csrk); 2530 log_info_key("csrk", setup->sm_local_csrk); 2531 if (setup->sm_key_distribution_send_set){ 2532 connection->sm_engine_state = SM_PH3_DISTRIBUTE_KEYS; 2533 } else { 2534 // no keys to send, just continue 2535 if (connection->sm_role){ 2536 // slave -> receive master keys 2537 connection->sm_engine_state = SM_PH3_RECEIVE_KEYS; 2538 } else { 2539 // master -> all done 2540 connection->sm_engine_state = SM_INITIATOR_CONNECTED; 2541 sm_done_for_handle(connection->sm_handle); 2542 } 2543 } 2544 return; 2545 case SM_RESPONDER_PH4_LTK_W4_ENC: 2546 reverse_128(data, setup->sm_ltk); 2547 sm_truncate_key(setup->sm_ltk, connection->sm_actual_encryption_key_size); 2548 log_info_key("ltk", setup->sm_ltk); 2549 connection->sm_engine_state = SM_RESPONDER_PH4_SEND_LTK; 2550 return; 2551 default: 2552 break; 2553 } 2554 } 2555 2556 #ifdef USE_MBEDTLS_FOR_ECDH 2557 2558 static void sm_log_ec_keypair(void){ 2559 // print keypair 2560 char buffer[100]; 2561 size_t len; 2562 mbedtls_mpi_write_string( &le_keypair.d, 16, buffer, sizeof(buffer), &len); 2563 log_info("d: %s", buffer); 2564 mbedtls_mpi_write_string( &le_keypair.Q.X, 16, buffer, sizeof(buffer), &len); 2565 log_info("X: %s", buffer); 2566 mbedtls_mpi_write_string( &le_keypair.Q.Y, 16, buffer, sizeof(buffer), &len); 2567 log_info("Y: %s", buffer); 2568 } 2569 2570 static int sm_generate_f_rng(void * context, unsigned char * buffer, size_t size){ 2571 int offset = setup->sm_passkey_bit; 2572 log_info("sm_generate_f_rng: size %u - offset %u", (int) size, offset); 2573 while (size) { 2574 if (offset < 32){ 2575 *buffer++ = setup->sm_peer_qx[offset++]; 2576 } else { 2577 *buffer++ = setup->sm_peer_qx[offset++ - 32]; 2578 } 2579 size--; 2580 } 2581 setup->sm_passkey_bit = offset; 2582 return 0; 2583 } 2584 #endif 2585 2586 // note: random generator is ready. this doesn NOT imply that aes engine is unused! 2587 static void sm_handle_random_result(uint8_t * data){ 2588 2589 #ifdef USE_MBEDTLS_FOR_ECDH 2590 if (ec_key_generation_state == EC_KEY_GENERATION_ACTIVE){ 2591 int num_bytes = setup->sm_passkey_bit; 2592 if (num_bytes < 32){ 2593 memcpy(&setup->sm_peer_qx[num_bytes], data, 8); 2594 } else { 2595 memcpy(&setup->sm_peer_qx[num_bytes-32], data, 8); 2596 } 2597 num_bytes += 8; 2598 setup->sm_passkey_bit = num_bytes; 2599 2600 if (num_bytes >= 64){ 2601 // generate EC key 2602 setup->sm_passkey_bit = 0; 2603 mbedtls_ecp_gen_key(MBEDTLS_ECP_DP_SECP256R1, &le_keypair, &sm_generate_f_rng, NULL); 2604 sm_log_ec_keypair(); 2605 ec_key_generation_state = EC_KEY_GENERATION_DONE; 2606 } 2607 } 2608 #endif 2609 2610 switch (rau_state){ 2611 case RAU_W4_RANDOM: 2612 // non-resolvable vs. resolvable 2613 switch (gap_random_adress_type){ 2614 case GAP_RANDOM_ADDRESS_RESOLVABLE: 2615 // resolvable: use random as prand and calc address hash 2616 // "The two most significant bits of prand shall be equal to ‘0’ and ‘1" 2617 memcpy(sm_random_address, data, 3); 2618 sm_random_address[0] &= 0x3f; 2619 sm_random_address[0] |= 0x40; 2620 rau_state = RAU_GET_ENC; 2621 break; 2622 case GAP_RANDOM_ADDRESS_NON_RESOLVABLE: 2623 default: 2624 // "The two most significant bits of the address shall be equal to ‘0’"" 2625 memcpy(sm_random_address, data, 6); 2626 sm_random_address[0] &= 0x3f; 2627 rau_state = RAU_SET_ADDRESS; 2628 break; 2629 } 2630 return; 2631 default: 2632 break; 2633 } 2634 2635 // retrieve sm_connection provided to sm_random_start 2636 sm_connection_t * connection = (sm_connection_t *) sm_random_context; 2637 if (!connection) return; 2638 switch (connection->sm_engine_state){ 2639 #ifdef ENABLE_LE_SECURE_CONNECTIONS 2640 case SM_SC_W4_GET_RANDOM_A: 2641 memcpy(&setup->sm_local_nonce[0], data, 8); 2642 connection->sm_engine_state = SM_SC_W2_GET_RANDOM_B; 2643 break; 2644 case SM_SC_W4_GET_RANDOM_B: 2645 memcpy(&setup->sm_local_nonce[8], data, 8); 2646 // initiator & jw/nc -> send pairing random 2647 if (connection->sm_role == 0 && sm_just_works_or_numeric_comparison(setup->sm_stk_generation_method)){ 2648 connection->sm_engine_state = SM_SC_SEND_PAIRING_RANDOM; 2649 break; 2650 } else { 2651 connection->sm_engine_state = SM_SC_W2_CMAC_FOR_CONFIRMATION; 2652 } 2653 break; 2654 #endif 2655 2656 case SM_PH2_W4_RANDOM_TK: 2657 { 2658 // map random to 0-999999 without speding much cycles on a modulus operation 2659 uint32_t tk = little_endian_read_32(data,0); 2660 tk = tk & 0xfffff; // 1048575 2661 if (tk >= 999999){ 2662 tk = tk - 999999; 2663 } 2664 sm_reset_tk(); 2665 big_endian_store_32(setup->sm_tk, 12, tk); 2666 if (connection->sm_role){ 2667 connection->sm_engine_state = SM_RESPONDER_PH1_SEND_PAIRING_RESPONSE; 2668 } else { 2669 connection->sm_engine_state = SM_PH1_W4_USER_RESPONSE; 2670 sm_trigger_user_response(connection); 2671 // response_idle == nothing <--> sm_trigger_user_response() did not require response 2672 if (setup->sm_user_response == SM_USER_RESPONSE_IDLE){ 2673 connection->sm_engine_state = SM_PH2_C1_GET_RANDOM_A; 2674 } 2675 } 2676 return; 2677 } 2678 case SM_PH2_C1_W4_RANDOM_A: 2679 memcpy(&setup->sm_local_random[0], data, 8); // random endinaness 2680 connection->sm_engine_state = SM_PH2_C1_GET_RANDOM_B; 2681 return; 2682 case SM_PH2_C1_W4_RANDOM_B: 2683 memcpy(&setup->sm_local_random[8], data, 8); // random endinaness 2684 connection->sm_engine_state = SM_PH2_C1_GET_ENC_A; 2685 return; 2686 case SM_PH3_W4_RANDOM: 2687 reverse_64(data, setup->sm_local_rand); 2688 // no db for encryption size hack: encryption size is stored in lowest nibble of setup->sm_local_rand 2689 setup->sm_local_rand[7] = (setup->sm_local_rand[7] & 0xf0) + (connection->sm_actual_encryption_key_size - 1); 2690 // no db for authenticated flag hack: store flag in bit 4 of LSB 2691 setup->sm_local_rand[7] = (setup->sm_local_rand[7] & 0xef) + (connection->sm_connection_authenticated << 4); 2692 connection->sm_engine_state = SM_PH3_GET_DIV; 2693 return; 2694 case SM_PH3_W4_DIV: 2695 // use 16 bit from random value as div 2696 setup->sm_local_div = big_endian_read_16(data, 0); 2697 log_info_hex16("div", setup->sm_local_div); 2698 connection->sm_engine_state = SM_PH3_Y_GET_ENC; 2699 return; 2700 default: 2701 break; 2702 } 2703 } 2704 2705 static void sm_event_packet_handler (uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size){ 2706 2707 sm_connection_t * sm_conn; 2708 hci_con_handle_t con_handle; 2709 2710 switch (packet_type) { 2711 2712 case HCI_EVENT_PACKET: 2713 switch (hci_event_packet_get_type(packet)) { 2714 2715 case BTSTACK_EVENT_STATE: 2716 // bt stack activated, get started 2717 if (btstack_event_state_get_state(packet) == HCI_STATE_WORKING){ 2718 log_info("HCI Working!"); 2719 dkg_state = sm_persistent_irk_ready ? DKG_CALC_DHK : DKG_CALC_IRK; 2720 rau_state = RAU_IDLE; 2721 #ifdef USE_MBEDTLS_FOR_ECDH 2722 if (!test_use_fixed_ec_keypair){ 2723 setup->sm_passkey_bit = 0; 2724 ec_key_generation_state = EC_KEY_GENERATION_ACTIVE; 2725 } 2726 #endif 2727 sm_run(); 2728 } 2729 break; 2730 2731 case HCI_EVENT_LE_META: 2732 switch (packet[2]) { 2733 case HCI_SUBEVENT_LE_CONNECTION_COMPLETE: 2734 2735 log_info("sm: connected"); 2736 2737 if (packet[3]) return; // connection failed 2738 2739 con_handle = little_endian_read_16(packet, 4); 2740 sm_conn = sm_get_connection_for_handle(con_handle); 2741 if (!sm_conn) break; 2742 2743 sm_conn->sm_handle = con_handle; 2744 sm_conn->sm_role = packet[6]; 2745 sm_conn->sm_peer_addr_type = packet[7]; 2746 reverse_bd_addr(&packet[8], 2747 sm_conn->sm_peer_address); 2748 2749 log_info("New sm_conn, role %s", sm_conn->sm_role ? "slave" : "master"); 2750 2751 // reset security properties 2752 sm_conn->sm_connection_encrypted = 0; 2753 sm_conn->sm_connection_authenticated = 0; 2754 sm_conn->sm_connection_authorization_state = AUTHORIZATION_UNKNOWN; 2755 sm_conn->sm_le_db_index = -1; 2756 2757 // prepare CSRK lookup (does not involve setup) 2758 sm_conn->sm_irk_lookup_state = IRK_LOOKUP_W4_READY; 2759 2760 // just connected -> everything else happens in sm_run() 2761 if (sm_conn->sm_role){ 2762 // slave - state already could be SM_RESPONDER_SEND_SECURITY_REQUEST instead 2763 if (sm_conn->sm_engine_state == SM_GENERAL_IDLE){ 2764 if (sm_slave_request_security) { 2765 // request security if requested by app 2766 sm_conn->sm_engine_state = SM_RESPONDER_SEND_SECURITY_REQUEST; 2767 } else { 2768 // otherwise, wait for pairing request 2769 sm_conn->sm_engine_state = SM_RESPONDER_IDLE; 2770 } 2771 } 2772 break; 2773 } else { 2774 // master 2775 sm_conn->sm_engine_state = SM_INITIATOR_CONNECTED; 2776 } 2777 break; 2778 2779 case HCI_SUBEVENT_LE_LONG_TERM_KEY_REQUEST: 2780 con_handle = little_endian_read_16(packet, 3); 2781 sm_conn = sm_get_connection_for_handle(con_handle); 2782 if (!sm_conn) break; 2783 2784 log_info("LTK Request: state %u", sm_conn->sm_engine_state); 2785 if (sm_conn->sm_engine_state == SM_RESPONDER_PH2_W4_LTK_REQUEST){ 2786 sm_conn->sm_engine_state = SM_PH2_CALC_STK; 2787 break; 2788 } 2789 if (sm_conn->sm_engine_state == SM_SC_W4_LTK_REQUEST_SC){ 2790 sm_conn->sm_engine_state = SM_RESPONDER_PH2_SEND_LTK_REPLY; 2791 break; 2792 } 2793 2794 // store rand and ediv 2795 reverse_64(&packet[5], sm_conn->sm_local_rand); 2796 sm_conn->sm_local_ediv = little_endian_read_16(packet, 13); 2797 sm_conn->sm_engine_state = SM_RESPONDER_PH0_RECEIVED_LTK; 2798 break; 2799 2800 default: 2801 break; 2802 } 2803 break; 2804 2805 case HCI_EVENT_ENCRYPTION_CHANGE: 2806 con_handle = little_endian_read_16(packet, 3); 2807 sm_conn = sm_get_connection_for_handle(con_handle); 2808 if (!sm_conn) break; 2809 2810 sm_conn->sm_connection_encrypted = packet[5]; 2811 log_info("Encryption state change: %u, key size %u", sm_conn->sm_connection_encrypted, 2812 sm_conn->sm_actual_encryption_key_size); 2813 log_info("event handler, state %u", sm_conn->sm_engine_state); 2814 if (!sm_conn->sm_connection_encrypted) break; 2815 // continue if part of initial pairing 2816 switch (sm_conn->sm_engine_state){ 2817 case SM_INITIATOR_PH0_W4_CONNECTION_ENCRYPTED: 2818 sm_conn->sm_engine_state = SM_INITIATOR_CONNECTED; 2819 sm_done_for_handle(sm_conn->sm_handle); 2820 break; 2821 case SM_PH2_W4_CONNECTION_ENCRYPTED: 2822 if (sm_conn->sm_role){ 2823 // slave 2824 sm_conn->sm_engine_state = SM_PH3_GET_RANDOM; 2825 } else { 2826 // master 2827 if (sm_key_distribution_all_received(sm_conn)){ 2828 // skip receiving keys as there are none 2829 sm_key_distribution_handle_all_received(sm_conn); 2830 sm_conn->sm_engine_state = SM_PH3_GET_RANDOM; 2831 } else { 2832 sm_conn->sm_engine_state = SM_PH3_RECEIVE_KEYS; 2833 } 2834 } 2835 break; 2836 default: 2837 break; 2838 } 2839 break; 2840 2841 case HCI_EVENT_ENCRYPTION_KEY_REFRESH_COMPLETE: 2842 con_handle = little_endian_read_16(packet, 3); 2843 sm_conn = sm_get_connection_for_handle(con_handle); 2844 if (!sm_conn) break; 2845 2846 log_info("Encryption key refresh complete, key size %u", sm_conn->sm_actual_encryption_key_size); 2847 log_info("event handler, state %u", sm_conn->sm_engine_state); 2848 // continue if part of initial pairing 2849 switch (sm_conn->sm_engine_state){ 2850 case SM_INITIATOR_PH0_W4_CONNECTION_ENCRYPTED: 2851 sm_conn->sm_engine_state = SM_INITIATOR_CONNECTED; 2852 sm_done_for_handle(sm_conn->sm_handle); 2853 break; 2854 case SM_PH2_W4_CONNECTION_ENCRYPTED: 2855 if (sm_conn->sm_role){ 2856 // slave 2857 sm_conn->sm_engine_state = SM_PH3_GET_RANDOM; 2858 } else { 2859 // master 2860 sm_conn->sm_engine_state = SM_PH3_RECEIVE_KEYS; 2861 } 2862 break; 2863 default: 2864 break; 2865 } 2866 break; 2867 2868 2869 case HCI_EVENT_DISCONNECTION_COMPLETE: 2870 con_handle = little_endian_read_16(packet, 3); 2871 sm_done_for_handle(con_handle); 2872 sm_conn = sm_get_connection_for_handle(con_handle); 2873 if (!sm_conn) break; 2874 2875 // delete stored bonding on disconnect with authentication failure in ph0 2876 if (sm_conn->sm_role == 0 2877 && sm_conn->sm_engine_state == SM_INITIATOR_PH0_W4_CONNECTION_ENCRYPTED 2878 && packet[2] == ERROR_CODE_AUTHENTICATION_FAILURE){ 2879 le_device_db_remove(sm_conn->sm_le_db_index); 2880 } 2881 2882 sm_conn->sm_engine_state = SM_GENERAL_IDLE; 2883 sm_conn->sm_handle = 0; 2884 break; 2885 2886 case HCI_EVENT_COMMAND_COMPLETE: 2887 if (HCI_EVENT_IS_COMMAND_COMPLETE(packet, hci_le_encrypt)){ 2888 sm_handle_encryption_result(&packet[6]); 2889 break; 2890 } 2891 if (HCI_EVENT_IS_COMMAND_COMPLETE(packet, hci_le_rand)){ 2892 sm_handle_random_result(&packet[6]); 2893 break; 2894 } 2895 break; 2896 default: 2897 break; 2898 } 2899 break; 2900 default: 2901 break; 2902 } 2903 2904 sm_run(); 2905 } 2906 2907 static inline int sm_calc_actual_encryption_key_size(int other){ 2908 if (other < sm_min_encryption_key_size) return 0; 2909 if (other < sm_max_encryption_key_size) return other; 2910 return sm_max_encryption_key_size; 2911 } 2912 2913 2914 static int sm_just_works_or_numeric_comparison(stk_generation_method_t method){ 2915 switch (method){ 2916 case JUST_WORKS: 2917 case NK_BOTH_INPUT: 2918 return 1; 2919 default: 2920 return 0; 2921 } 2922 } 2923 // responder 2924 2925 static int sm_passkey_used(stk_generation_method_t method){ 2926 switch (method){ 2927 case PK_RESP_INPUT: 2928 return 1; 2929 default: 2930 return 0; 2931 } 2932 } 2933 2934 /** 2935 * @return ok 2936 */ 2937 static int sm_validate_stk_generation_method(void){ 2938 // check if STK generation method is acceptable by client 2939 switch (setup->sm_stk_generation_method){ 2940 case JUST_WORKS: 2941 return (sm_accepted_stk_generation_methods & SM_STK_GENERATION_METHOD_JUST_WORKS) != 0; 2942 case PK_RESP_INPUT: 2943 case PK_INIT_INPUT: 2944 case OK_BOTH_INPUT: 2945 return (sm_accepted_stk_generation_methods & SM_STK_GENERATION_METHOD_PASSKEY) != 0; 2946 case OOB: 2947 return (sm_accepted_stk_generation_methods & SM_STK_GENERATION_METHOD_OOB) != 0; 2948 case NK_BOTH_INPUT: 2949 return (sm_accepted_stk_generation_methods & SM_STK_GENERATION_METHOD_NUMERIC_COMPARISON) != 0; 2950 return 1; 2951 default: 2952 return 0; 2953 } 2954 } 2955 2956 static void sm_pdu_handler(uint8_t packet_type, hci_con_handle_t con_handle, uint8_t *packet, uint16_t size){ 2957 2958 if (packet_type == HCI_EVENT_PACKET && packet[0] == L2CAP_EVENT_CAN_SEND_NOW){ 2959 sm_run(); 2960 } 2961 2962 if (packet_type != SM_DATA_PACKET) return; 2963 2964 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 2965 if (!sm_conn) return; 2966 2967 if (packet[0] == SM_CODE_PAIRING_FAILED){ 2968 sm_conn->sm_engine_state = sm_conn->sm_role ? SM_RESPONDER_IDLE : SM_INITIATOR_CONNECTED; 2969 return; 2970 } 2971 2972 log_debug("sm_pdu_handler: state %u, pdu 0x%02x", sm_conn->sm_engine_state, packet[0]); 2973 2974 int err; 2975 2976 switch (sm_conn->sm_engine_state){ 2977 2978 // a sm timeout requries a new physical connection 2979 case SM_GENERAL_TIMEOUT: 2980 return; 2981 2982 // Initiator 2983 case SM_INITIATOR_CONNECTED: 2984 if ((packet[0] != SM_CODE_SECURITY_REQUEST) || (sm_conn->sm_role)){ 2985 sm_pdu_received_in_wrong_state(sm_conn); 2986 break; 2987 } 2988 if (sm_conn->sm_irk_lookup_state == IRK_LOOKUP_FAILED){ 2989 sm_conn->sm_engine_state = SM_INITIATOR_PH1_W2_SEND_PAIRING_REQUEST; 2990 break; 2991 } 2992 if (sm_conn->sm_irk_lookup_state == IRK_LOOKUP_SUCCEEDED){ 2993 uint16_t ediv; 2994 le_device_db_encryption_get(sm_conn->sm_le_db_index, &ediv, NULL, NULL, NULL, NULL, NULL); 2995 if (ediv){ 2996 log_info("sm: Setting up previous ltk/ediv/rand for device index %u", sm_conn->sm_le_db_index); 2997 sm_conn->sm_engine_state = SM_INITIATOR_PH0_HAS_LTK; 2998 } else { 2999 sm_conn->sm_engine_state = SM_INITIATOR_PH1_W2_SEND_PAIRING_REQUEST; 3000 } 3001 break; 3002 } 3003 // otherwise, store security request 3004 sm_conn->sm_security_request_received = 1; 3005 break; 3006 3007 case SM_INITIATOR_PH1_W4_PAIRING_RESPONSE: 3008 if (packet[0] != SM_CODE_PAIRING_RESPONSE){ 3009 sm_pdu_received_in_wrong_state(sm_conn); 3010 break; 3011 } 3012 // store pairing request 3013 memcpy(&setup->sm_s_pres, packet, sizeof(sm_pairing_packet_t)); 3014 err = sm_stk_generation_init(sm_conn); 3015 if (err){ 3016 setup->sm_pairing_failed_reason = err; 3017 sm_conn->sm_engine_state = SM_GENERAL_SEND_PAIRING_FAILED; 3018 break; 3019 } 3020 #ifdef ENABLE_LE_SECURE_CONNECTIONS 3021 if (setup->sm_use_secure_connections){ 3022 // SC Numeric Comparison will trigger user response after public keys & nonces have been exchanged 3023 if (setup->sm_stk_generation_method == JUST_WORKS){ 3024 sm_conn->sm_engine_state = SM_PH1_W4_USER_RESPONSE; 3025 sm_trigger_user_response(sm_conn); 3026 if (setup->sm_user_response == SM_USER_RESPONSE_IDLE){ 3027 sm_conn->sm_engine_state = SM_SC_SEND_PUBLIC_KEY_COMMAND; 3028 } 3029 } else { 3030 sm_conn->sm_engine_state = SM_SC_SEND_PUBLIC_KEY_COMMAND; 3031 } 3032 break; 3033 } 3034 #endif 3035 // generate random number first, if we need to show passkey 3036 if (setup->sm_stk_generation_method == PK_RESP_INPUT){ 3037 sm_conn->sm_engine_state = SM_PH2_GET_RANDOM_TK; 3038 break; 3039 } 3040 sm_conn->sm_engine_state = SM_PH1_W4_USER_RESPONSE; 3041 sm_trigger_user_response(sm_conn); 3042 // response_idle == nothing <--> sm_trigger_user_response() did not require response 3043 if (setup->sm_user_response == SM_USER_RESPONSE_IDLE){ 3044 sm_conn->sm_engine_state = SM_PH2_C1_GET_RANDOM_A; 3045 } 3046 break; 3047 3048 case SM_INITIATOR_PH2_W4_PAIRING_CONFIRM: 3049 if (packet[0] != SM_CODE_PAIRING_CONFIRM){ 3050 sm_pdu_received_in_wrong_state(sm_conn); 3051 break; 3052 } 3053 3054 // store s_confirm 3055 reverse_128(&packet[1], setup->sm_peer_confirm); 3056 sm_conn->sm_engine_state = SM_PH2_SEND_PAIRING_RANDOM; 3057 break; 3058 3059 case SM_INITIATOR_PH2_W4_PAIRING_RANDOM: 3060 if (packet[0] != SM_CODE_PAIRING_RANDOM){ 3061 sm_pdu_received_in_wrong_state(sm_conn); 3062 break;; 3063 } 3064 3065 // received random value 3066 reverse_128(&packet[1], setup->sm_peer_random); 3067 sm_conn->sm_engine_state = SM_PH2_C1_GET_ENC_C; 3068 break; 3069 3070 // Responder 3071 case SM_RESPONDER_IDLE: 3072 case SM_RESPONDER_SEND_SECURITY_REQUEST: 3073 case SM_RESPONDER_PH1_W4_PAIRING_REQUEST: 3074 if (packet[0] != SM_CODE_PAIRING_REQUEST){ 3075 sm_pdu_received_in_wrong_state(sm_conn); 3076 break;; 3077 } 3078 3079 // store pairing request 3080 memcpy(&sm_conn->sm_m_preq, packet, sizeof(sm_pairing_packet_t)); 3081 sm_conn->sm_engine_state = SM_RESPONDER_PH1_PAIRING_REQUEST_RECEIVED; 3082 break; 3083 3084 #ifdef ENABLE_LE_SECURE_CONNECTIONS 3085 case SM_SC_W4_PUBLIC_KEY_COMMAND: 3086 if (packet[0] != SM_CODE_PAIRING_PUBLIC_KEY){ 3087 sm_pdu_received_in_wrong_state(sm_conn); 3088 break; 3089 } 3090 3091 // store public key for DH Key calculation 3092 reverse_256(&packet[01], setup->sm_peer_qx); 3093 reverse_256(&packet[33], setup->sm_peer_qy); 3094 3095 #ifdef USE_MBEDTLS_FOR_ECDH 3096 // validate public key 3097 mbedtls_ecp_group grp; 3098 mbedtls_ecp_group_init( &grp ); 3099 mbedtls_ecp_group_load(&grp, MBEDTLS_ECP_DP_SECP256R1); 3100 3101 mbedtls_ecp_point Q; 3102 mbedtls_ecp_point_init( &Q ); 3103 mbedtls_mpi_read_binary(&Q.X, setup->sm_peer_qx, 32); 3104 mbedtls_mpi_read_binary(&Q.Y, setup->sm_peer_qy, 32); 3105 mbedtls_mpi_read_string(&Q.Z, 16, "1" ); 3106 err = mbedtls_ecp_check_pubkey(&grp, &Q); 3107 if (err){ 3108 log_error("sm: peer public key invalid %x", err); 3109 // uses "unspecified reason", there is no "public key invalid" error code 3110 sm_pdu_received_in_wrong_state(sm_conn); 3111 break; 3112 } 3113 #endif 3114 if (sm_conn->sm_role){ 3115 // responder 3116 sm_conn->sm_engine_state = SM_SC_SEND_PUBLIC_KEY_COMMAND; 3117 } else { 3118 // initiator 3119 // stk generation method 3120 // passkey entry: notify app to show passkey or to request passkey 3121 switch (setup->sm_stk_generation_method){ 3122 case JUST_WORKS: 3123 case NK_BOTH_INPUT: 3124 sm_conn->sm_engine_state = SM_SC_W4_CONFIRMATION; 3125 break; 3126 case PK_RESP_INPUT: 3127 sm_sc_start_calculating_local_confirm(sm_conn); 3128 break; 3129 case PK_INIT_INPUT: 3130 case OK_BOTH_INPUT: 3131 if (setup->sm_user_response != SM_USER_RESPONSE_PASSKEY){ 3132 sm_conn->sm_engine_state = SM_SC_W4_USER_RESPONSE; 3133 break; 3134 } 3135 sm_sc_start_calculating_local_confirm(sm_conn); 3136 break; 3137 case OOB: 3138 // TODO: implement SC OOB 3139 break; 3140 } 3141 } 3142 break; 3143 3144 case SM_SC_W4_CONFIRMATION: 3145 if (packet[0] != SM_CODE_PAIRING_CONFIRM){ 3146 sm_pdu_received_in_wrong_state(sm_conn); 3147 break; 3148 } 3149 // received confirm value 3150 reverse_128(&packet[1], setup->sm_peer_confirm); 3151 3152 if (sm_conn->sm_role){ 3153 // responder 3154 if (sm_passkey_used(setup->sm_stk_generation_method)){ 3155 if (setup->sm_user_response != SM_USER_RESPONSE_PASSKEY){ 3156 // still waiting for passkey 3157 sm_conn->sm_engine_state = SM_SC_W4_USER_RESPONSE; 3158 break; 3159 } 3160 } 3161 sm_sc_start_calculating_local_confirm(sm_conn); 3162 } else { 3163 // initiator 3164 if (sm_just_works_or_numeric_comparison(setup->sm_stk_generation_method)){ 3165 sm_conn->sm_engine_state = SM_SC_W2_GET_RANDOM_A; 3166 } else { 3167 sm_conn->sm_engine_state = SM_SC_SEND_PAIRING_RANDOM; 3168 } 3169 } 3170 break; 3171 3172 case SM_SC_W4_PAIRING_RANDOM: 3173 if (packet[0] != SM_CODE_PAIRING_RANDOM){ 3174 sm_pdu_received_in_wrong_state(sm_conn); 3175 break; 3176 } 3177 3178 // received random value 3179 reverse_128(&packet[1], setup->sm_peer_nonce); 3180 3181 // validate confirm value if Cb = f4(Pkb, Pka, Nb, z) 3182 // only check for JUST WORK/NC in initiator role AND passkey entry 3183 int passkey_entry = sm_passkey_used(setup->sm_stk_generation_method); 3184 if (sm_conn->sm_role || passkey_entry) { 3185 sm_conn->sm_engine_state = SM_SC_W2_CMAC_FOR_CHECK_CONFIRMATION; 3186 } 3187 3188 sm_sc_state_after_receiving_random(sm_conn); 3189 break; 3190 3191 case SM_SC_W2_CALCULATE_G2: 3192 case SM_SC_W4_CALCULATE_G2: 3193 case SM_SC_W2_CALCULATE_F5_SALT: 3194 case SM_SC_W4_CALCULATE_F5_SALT: 3195 case SM_SC_W2_CALCULATE_F5_MACKEY: 3196 case SM_SC_W4_CALCULATE_F5_MACKEY: 3197 case SM_SC_W2_CALCULATE_F5_LTK: 3198 case SM_SC_W4_CALCULATE_F5_LTK: 3199 case SM_SC_W2_CALCULATE_F6_FOR_DHKEY_CHECK: 3200 case SM_SC_W4_DHKEY_CHECK_COMMAND: 3201 case SM_SC_W4_CALCULATE_F6_FOR_DHKEY_CHECK: 3202 if (packet[0] != SM_CODE_PAIRING_DHKEY_CHECK){ 3203 sm_pdu_received_in_wrong_state(sm_conn); 3204 break; 3205 } 3206 // store DHKey Check 3207 setup->sm_state_vars |= SM_STATE_VAR_DHKEY_COMMAND_RECEIVED; 3208 reverse_128(&packet[01], setup->sm_peer_dhkey_check); 3209 3210 // have we been only waiting for dhkey check command? 3211 if (sm_conn->sm_engine_state == SM_SC_W4_DHKEY_CHECK_COMMAND){ 3212 sm_conn->sm_engine_state = SM_SC_W2_CALCULATE_F6_TO_VERIFY_DHKEY_CHECK; 3213 } 3214 break; 3215 #endif 3216 3217 case SM_RESPONDER_PH1_W4_PAIRING_CONFIRM: 3218 if (packet[0] != SM_CODE_PAIRING_CONFIRM){ 3219 sm_pdu_received_in_wrong_state(sm_conn); 3220 break; 3221 } 3222 3223 // received confirm value 3224 reverse_128(&packet[1], setup->sm_peer_confirm); 3225 3226 // notify client to hide shown passkey 3227 if (setup->sm_stk_generation_method == PK_INIT_INPUT){ 3228 sm_notify_client_base(SM_EVENT_PASSKEY_DISPLAY_CANCEL, sm_conn->sm_handle, sm_conn->sm_peer_addr_type, sm_conn->sm_peer_address); 3229 } 3230 3231 // handle user cancel pairing? 3232 if (setup->sm_user_response == SM_USER_RESPONSE_DECLINE){ 3233 setup->sm_pairing_failed_reason = SM_REASON_PASSKEYT_ENTRY_FAILED; 3234 sm_conn->sm_engine_state = SM_GENERAL_SEND_PAIRING_FAILED; 3235 break; 3236 } 3237 3238 // wait for user action? 3239 if (setup->sm_user_response == SM_USER_RESPONSE_PENDING){ 3240 sm_conn->sm_engine_state = SM_PH1_W4_USER_RESPONSE; 3241 break; 3242 } 3243 3244 // calculate and send local_confirm 3245 sm_conn->sm_engine_state = SM_PH2_C1_GET_RANDOM_A; 3246 break; 3247 3248 case SM_RESPONDER_PH2_W4_PAIRING_RANDOM: 3249 if (packet[0] != SM_CODE_PAIRING_RANDOM){ 3250 sm_pdu_received_in_wrong_state(sm_conn); 3251 break;; 3252 } 3253 3254 // received random value 3255 reverse_128(&packet[1], setup->sm_peer_random); 3256 sm_conn->sm_engine_state = SM_PH2_C1_GET_ENC_C; 3257 break; 3258 3259 case SM_PH3_RECEIVE_KEYS: 3260 switch(packet[0]){ 3261 case SM_CODE_ENCRYPTION_INFORMATION: 3262 setup->sm_key_distribution_received_set |= SM_KEYDIST_FLAG_ENCRYPTION_INFORMATION; 3263 reverse_128(&packet[1], setup->sm_peer_ltk); 3264 break; 3265 3266 case SM_CODE_MASTER_IDENTIFICATION: 3267 setup->sm_key_distribution_received_set |= SM_KEYDIST_FLAG_MASTER_IDENTIFICATION; 3268 setup->sm_peer_ediv = little_endian_read_16(packet, 1); 3269 reverse_64(&packet[3], setup->sm_peer_rand); 3270 break; 3271 3272 case SM_CODE_IDENTITY_INFORMATION: 3273 setup->sm_key_distribution_received_set |= SM_KEYDIST_FLAG_IDENTITY_INFORMATION; 3274 reverse_128(&packet[1], setup->sm_peer_irk); 3275 break; 3276 3277 case SM_CODE_IDENTITY_ADDRESS_INFORMATION: 3278 setup->sm_key_distribution_received_set |= SM_KEYDIST_FLAG_IDENTITY_ADDRESS_INFORMATION; 3279 setup->sm_peer_addr_type = packet[1]; 3280 reverse_bd_addr(&packet[2], setup->sm_peer_address); 3281 break; 3282 3283 case SM_CODE_SIGNING_INFORMATION: 3284 setup->sm_key_distribution_received_set |= SM_KEYDIST_FLAG_SIGNING_IDENTIFICATION; 3285 reverse_128(&packet[1], setup->sm_peer_csrk); 3286 break; 3287 default: 3288 // Unexpected PDU 3289 log_info("Unexpected PDU %u in SM_PH3_RECEIVE_KEYS", packet[0]); 3290 break; 3291 } 3292 // done with key distribution? 3293 if (sm_key_distribution_all_received(sm_conn)){ 3294 3295 sm_key_distribution_handle_all_received(sm_conn); 3296 3297 if (sm_conn->sm_role){ 3298 sm_conn->sm_engine_state = SM_RESPONDER_IDLE; 3299 sm_done_for_handle(sm_conn->sm_handle); 3300 } else { 3301 sm_conn->sm_engine_state = SM_PH3_GET_RANDOM; 3302 #ifdef ENABLE_LE_SECURE_CONNECTIONS 3303 if (setup->sm_use_secure_connections){ 3304 sm_conn->sm_engine_state = SM_PH3_DISTRIBUTE_KEYS; 3305 } 3306 #endif 3307 } 3308 } 3309 break; 3310 default: 3311 // Unexpected PDU 3312 log_info("Unexpected PDU %u in state %u", packet[0], sm_conn->sm_engine_state); 3313 break; 3314 } 3315 3316 // try to send preparared packet 3317 sm_run(); 3318 } 3319 3320 // Security Manager Client API 3321 void sm_register_oob_data_callback( int (*get_oob_data_callback)(uint8_t addres_type, bd_addr_t addr, uint8_t * oob_data)){ 3322 sm_get_oob_data = get_oob_data_callback; 3323 } 3324 3325 void sm_add_event_handler(btstack_packet_callback_registration_t * callback_handler){ 3326 btstack_linked_list_add_tail(&sm_event_handlers, (btstack_linked_item_t*) callback_handler); 3327 } 3328 3329 void sm_set_accepted_stk_generation_methods(uint8_t accepted_stk_generation_methods){ 3330 sm_accepted_stk_generation_methods = accepted_stk_generation_methods; 3331 } 3332 3333 void sm_set_encryption_key_size_range(uint8_t min_size, uint8_t max_size){ 3334 sm_min_encryption_key_size = min_size; 3335 sm_max_encryption_key_size = max_size; 3336 } 3337 3338 void sm_set_authentication_requirements(uint8_t auth_req){ 3339 sm_auth_req = auth_req; 3340 } 3341 3342 void sm_set_io_capabilities(io_capability_t io_capability){ 3343 sm_io_capabilities = io_capability; 3344 } 3345 3346 void sm_set_request_security(int enable){ 3347 sm_slave_request_security = enable; 3348 } 3349 3350 void sm_set_er(sm_key_t er){ 3351 memcpy(sm_persistent_er, er, 16); 3352 } 3353 3354 void sm_set_ir(sm_key_t ir){ 3355 memcpy(sm_persistent_ir, ir, 16); 3356 } 3357 3358 // Testing support only 3359 void sm_test_set_irk(sm_key_t irk){ 3360 memcpy(sm_persistent_irk, irk, 16); 3361 sm_persistent_irk_ready = 1; 3362 } 3363 3364 void sm_test_use_fixed_local_csrk(void){ 3365 test_use_fixed_local_csrk = 1; 3366 } 3367 3368 void sm_init(void){ 3369 // set some (BTstack default) ER and IR 3370 int i; 3371 sm_key_t er; 3372 sm_key_t ir; 3373 for (i=0;i<16;i++){ 3374 er[i] = 0x30 + i; 3375 ir[i] = 0x90 + i; 3376 } 3377 sm_set_er(er); 3378 sm_set_ir(ir); 3379 // defaults 3380 sm_accepted_stk_generation_methods = SM_STK_GENERATION_METHOD_JUST_WORKS 3381 | SM_STK_GENERATION_METHOD_OOB 3382 | SM_STK_GENERATION_METHOD_PASSKEY 3383 | SM_STK_GENERATION_METHOD_NUMERIC_COMPARISON; 3384 3385 sm_max_encryption_key_size = 16; 3386 sm_min_encryption_key_size = 7; 3387 3388 sm_cmac_state = CMAC_IDLE; 3389 dkg_state = DKG_W4_WORKING; 3390 rau_state = RAU_W4_WORKING; 3391 sm_aes128_state = SM_AES128_IDLE; 3392 sm_address_resolution_test = -1; // no private address to resolve yet 3393 sm_address_resolution_ah_calculation_active = 0; 3394 sm_address_resolution_mode = ADDRESS_RESOLUTION_IDLE; 3395 sm_address_resolution_general_queue = NULL; 3396 3397 gap_random_adress_update_period = 15 * 60 * 1000L; 3398 3399 sm_active_connection = 0; 3400 3401 test_use_fixed_local_csrk = 0; 3402 3403 // register for HCI Events from HCI 3404 hci_event_callback_registration.callback = &sm_event_packet_handler; 3405 hci_add_event_handler(&hci_event_callback_registration); 3406 3407 // and L2CAP PDUs + L2CAP_EVENT_CAN_SEND_NOW 3408 l2cap_register_fixed_channel(sm_pdu_handler, L2CAP_CID_SECURITY_MANAGER_PROTOCOL); 3409 3410 #ifdef USE_MBEDTLS_FOR_ECDH 3411 ec_key_generation_state = EC_KEY_GENERATION_IDLE; 3412 #endif 3413 } 3414 3415 void sm_test_use_fixed_ec_keypair(void){ 3416 test_use_fixed_ec_keypair = 1; 3417 #ifdef USE_MBEDTLS_FOR_ECDH 3418 // use test keypair from spec 3419 mbedtls_ecp_keypair_init(&le_keypair); 3420 mbedtls_ecp_group_load(&le_keypair.grp, MBEDTLS_ECP_DP_SECP256R1); 3421 mbedtls_mpi_read_string( &le_keypair.d, 16, "3f49f6d4a3c55f3874c9b3e3d2103f504aff607beb40b7995899b8a6cd3c1abd"); 3422 mbedtls_mpi_read_string( &le_keypair.Q.X, 16, "20b003d2f297be2c5e2c83a7e9f9a5b9eff49111acf4fddbcc0301480e359de6"); 3423 mbedtls_mpi_read_string( &le_keypair.Q.Y, 16, "dc809c49652aeb6d63329abf5a52155c766345c28fed3024741c8ed01589d28b"); 3424 mbedtls_mpi_read_string( &le_keypair.Q.Z, 16, "1"); 3425 #endif 3426 } 3427 3428 static sm_connection_t * sm_get_connection_for_handle(hci_con_handle_t con_handle){ 3429 hci_connection_t * hci_con = hci_connection_for_handle(con_handle); 3430 if (!hci_con) return NULL; 3431 return &hci_con->sm_connection; 3432 } 3433 3434 // @returns 0 if not encrypted, 7-16 otherwise 3435 int sm_encryption_key_size(hci_con_handle_t con_handle){ 3436 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 3437 if (!sm_conn) return 0; // wrong connection 3438 if (!sm_conn->sm_connection_encrypted) return 0; 3439 return sm_conn->sm_actual_encryption_key_size; 3440 } 3441 3442 int sm_authenticated(hci_con_handle_t con_handle){ 3443 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 3444 if (!sm_conn) return 0; // wrong connection 3445 if (!sm_conn->sm_connection_encrypted) return 0; // unencrypted connection cannot be authenticated 3446 return sm_conn->sm_connection_authenticated; 3447 } 3448 3449 authorization_state_t sm_authorization_state(hci_con_handle_t con_handle){ 3450 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 3451 if (!sm_conn) return AUTHORIZATION_UNKNOWN; // wrong connection 3452 if (!sm_conn->sm_connection_encrypted) return AUTHORIZATION_UNKNOWN; // unencrypted connection cannot be authorized 3453 if (!sm_conn->sm_connection_authenticated) return AUTHORIZATION_UNKNOWN; // unauthenticatd connection cannot be authorized 3454 return sm_conn->sm_connection_authorization_state; 3455 } 3456 3457 static void sm_send_security_request_for_connection(sm_connection_t * sm_conn){ 3458 switch (sm_conn->sm_engine_state){ 3459 case SM_GENERAL_IDLE: 3460 case SM_RESPONDER_IDLE: 3461 sm_conn->sm_engine_state = SM_RESPONDER_SEND_SECURITY_REQUEST; 3462 sm_run(); 3463 break; 3464 default: 3465 break; 3466 } 3467 } 3468 3469 /** 3470 * @brief Trigger Security Request 3471 */ 3472 void sm_send_security_request(hci_con_handle_t con_handle){ 3473 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 3474 if (!sm_conn) return; 3475 sm_send_security_request_for_connection(sm_conn); 3476 } 3477 3478 // request pairing 3479 void sm_request_pairing(hci_con_handle_t con_handle){ 3480 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 3481 if (!sm_conn) return; // wrong connection 3482 3483 log_info("sm_request_pairing in role %u, state %u", sm_conn->sm_role, sm_conn->sm_engine_state); 3484 if (sm_conn->sm_role){ 3485 sm_send_security_request_for_connection(sm_conn); 3486 } else { 3487 // used as a trigger to start central/master/initiator security procedures 3488 uint16_t ediv; 3489 if (sm_conn->sm_engine_state == SM_INITIATOR_CONNECTED){ 3490 switch (sm_conn->sm_irk_lookup_state){ 3491 case IRK_LOOKUP_FAILED: 3492 sm_conn->sm_engine_state = SM_INITIATOR_PH1_W2_SEND_PAIRING_REQUEST; 3493 break; 3494 case IRK_LOOKUP_SUCCEEDED: 3495 le_device_db_encryption_get(sm_conn->sm_le_db_index, &ediv, NULL, NULL, NULL, NULL, NULL); 3496 if (ediv){ 3497 log_info("sm: Setting up previous ltk/ediv/rand for device index %u", sm_conn->sm_le_db_index); 3498 sm_conn->sm_engine_state = SM_INITIATOR_PH0_HAS_LTK; 3499 } else { 3500 sm_conn->sm_engine_state = SM_INITIATOR_PH1_W2_SEND_PAIRING_REQUEST; 3501 } 3502 break; 3503 default: 3504 sm_conn->sm_bonding_requested = 1; 3505 break; 3506 } 3507 } else if (sm_conn->sm_engine_state == SM_GENERAL_IDLE){ 3508 sm_conn->sm_bonding_requested = 1; 3509 } 3510 } 3511 sm_run(); 3512 } 3513 3514 // called by client app on authorization request 3515 void sm_authorization_decline(hci_con_handle_t con_handle){ 3516 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 3517 if (!sm_conn) return; // wrong connection 3518 sm_conn->sm_connection_authorization_state = AUTHORIZATION_DECLINED; 3519 sm_notify_client_authorization(SM_EVENT_AUTHORIZATION_RESULT, sm_conn->sm_handle, sm_conn->sm_peer_addr_type, sm_conn->sm_peer_address, 0); 3520 } 3521 3522 void sm_authorization_grant(hci_con_handle_t con_handle){ 3523 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 3524 if (!sm_conn) return; // wrong connection 3525 sm_conn->sm_connection_authorization_state = AUTHORIZATION_GRANTED; 3526 sm_notify_client_authorization(SM_EVENT_AUTHORIZATION_RESULT, sm_conn->sm_handle, sm_conn->sm_peer_addr_type, sm_conn->sm_peer_address, 1); 3527 } 3528 3529 // GAP Bonding API 3530 3531 void sm_bonding_decline(hci_con_handle_t con_handle){ 3532 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 3533 if (!sm_conn) return; // wrong connection 3534 setup->sm_user_response = SM_USER_RESPONSE_DECLINE; 3535 3536 if (sm_conn->sm_engine_state == SM_PH1_W4_USER_RESPONSE){ 3537 switch (setup->sm_stk_generation_method){ 3538 case PK_RESP_INPUT: 3539 case PK_INIT_INPUT: 3540 case OK_BOTH_INPUT: 3541 sm_pairing_error(sm_conn, SM_GENERAL_SEND_PAIRING_FAILED); 3542 break; 3543 case NK_BOTH_INPUT: 3544 sm_pairing_error(sm_conn, SM_REASON_NUMERIC_COMPARISON_FAILED); 3545 break; 3546 case JUST_WORKS: 3547 case OOB: 3548 sm_pairing_error(sm_conn, SM_REASON_UNSPECIFIED_REASON); 3549 break; 3550 } 3551 } 3552 sm_run(); 3553 } 3554 3555 void sm_just_works_confirm(hci_con_handle_t con_handle){ 3556 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 3557 if (!sm_conn) return; // wrong connection 3558 setup->sm_user_response = SM_USER_RESPONSE_CONFIRM; 3559 if (sm_conn->sm_engine_state == SM_PH1_W4_USER_RESPONSE){ 3560 sm_conn->sm_engine_state = SM_PH2_C1_GET_RANDOM_A; 3561 3562 #ifdef ENABLE_LE_SECURE_CONNECTIONS 3563 if (setup->sm_use_secure_connections){ 3564 sm_conn->sm_engine_state = SM_SC_SEND_PUBLIC_KEY_COMMAND; 3565 } 3566 #endif 3567 } 3568 3569 #ifdef ENABLE_LE_SECURE_CONNECTIONS 3570 if (sm_conn->sm_engine_state == SM_SC_W4_USER_RESPONSE){ 3571 sm_sc_prepare_dhkey_check(sm_conn); 3572 } 3573 #endif 3574 3575 sm_run(); 3576 } 3577 3578 void sm_numeric_comparison_confirm(hci_con_handle_t con_handle){ 3579 // for now, it's the same 3580 sm_just_works_confirm(con_handle); 3581 } 3582 3583 void sm_passkey_input(hci_con_handle_t con_handle, uint32_t passkey){ 3584 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 3585 if (!sm_conn) return; // wrong connection 3586 sm_reset_tk(); 3587 big_endian_store_32(setup->sm_tk, 12, passkey); 3588 setup->sm_user_response = SM_USER_RESPONSE_PASSKEY; 3589 if (sm_conn->sm_engine_state == SM_PH1_W4_USER_RESPONSE){ 3590 sm_conn->sm_engine_state = SM_PH2_C1_GET_RANDOM_A; 3591 } 3592 #ifdef ENABLE_LE_SECURE_CONNECTIONS 3593 memcpy(setup->sm_ra, setup->sm_tk, 16); 3594 memcpy(setup->sm_rb, setup->sm_tk, 16); 3595 if (sm_conn->sm_engine_state == SM_SC_W4_USER_RESPONSE){ 3596 sm_sc_start_calculating_local_confirm(sm_conn); 3597 } 3598 #endif 3599 sm_run(); 3600 } 3601 3602 /** 3603 * @brief Identify device in LE Device DB 3604 * @param handle 3605 * @returns index from le_device_db or -1 if not found/identified 3606 */ 3607 int sm_le_device_index(hci_con_handle_t con_handle ){ 3608 sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); 3609 if (!sm_conn) return -1; 3610 return sm_conn->sm_le_db_index; 3611 } 3612 3613 // GAP LE API 3614 void gap_random_address_set_mode(gap_random_address_type_t random_address_type){ 3615 gap_random_address_update_stop(); 3616 gap_random_adress_type = random_address_type; 3617 if (random_address_type == GAP_RANDOM_ADDRESS_TYPE_OFF) return; 3618 gap_random_address_update_start(); 3619 gap_random_address_trigger(); 3620 } 3621 3622 gap_random_address_type_t gap_random_address_get_mode(void){ 3623 return gap_random_adress_type; 3624 } 3625 3626 void gap_random_address_set_update_period(int period_ms){ 3627 gap_random_adress_update_period = period_ms; 3628 if (gap_random_adress_type == GAP_RANDOM_ADDRESS_TYPE_OFF) return; 3629 gap_random_address_update_stop(); 3630 gap_random_address_update_start(); 3631 } 3632 3633 void gap_random_address_set(bd_addr_t addr){ 3634 gap_random_address_set_mode(GAP_RANDOM_ADDRESS_TYPE_OFF); 3635 memcpy(sm_random_address, addr, 6); 3636 rau_state = RAU_SET_ADDRESS; 3637 sm_run(); 3638 } 3639 3640 /* 3641 * @brief Set Advertisement Paramters 3642 * @param adv_int_min 3643 * @param adv_int_max 3644 * @param adv_type 3645 * @param direct_address_type 3646 * @param direct_address 3647 * @param channel_map 3648 * @param filter_policy 3649 * 3650 * @note own_address_type is used from gap_random_address_set_mode 3651 */ 3652 void gap_advertisements_set_params(uint16_t adv_int_min, uint16_t adv_int_max, uint8_t adv_type, 3653 uint8_t direct_address_typ, bd_addr_t direct_address, uint8_t channel_map, uint8_t filter_policy){ 3654 hci_le_advertisements_set_params(adv_int_min, adv_int_max, adv_type, gap_random_adress_type, 3655 direct_address_typ, direct_address, channel_map, filter_policy); 3656 } 3657 3658